Processing aids for elastomeric compositions

ABSTRACT

The invention provides for processes to produce elastomeric compositions, the processes including contacting at least one elastomer with a processing aid, wherein the processing aid comprises at least one functionalized polymer having at least one anhydride group. The invention also provides for articles such as innerliners for tires produced from the aforementioned elastomeric compositions.

The present application claims the benefit of PCT Application No.PCT/US2005/045,978 filed on 16 Dec. 2005, the disclosure of which isincorporated by reference.

FIELD OF THE INVENTION

The invention relates to processing aids for use in the production ofelastomeric compositions. In particular, the invention relates toprocessing aids including functionalized polymers for use in theproduction of elastomeric compositions.

BACKGROUND

In the tire industry, manufacturers of tires and tire components haveendless choices when fabricating such items. For example, the selectionof ingredients for the commercial formulations of tires and tirecomponents depends upon the balance of properties desired and the enduse such as bias or radial, and its intended end use (e.g., aircraft,truck/bus, or automobile).

An equally important consideration in the selection of ingredients canbe the ability to efficiently process the individual components intobatch rubber mixes, and then the further downstream processing of thoseuncured rubber mixes. For example dry solids, particularly dust-freeparticles like fillers, may be easily air-conveyed and automaticallyweighed into the required amounts for batch production in internalmixers such as Banbury™ mixers. Bulk solids such as baled polymers, mayrequire cutting into smaller more manageable sizes so that requiredamounts for batch production are exactly added. Liquids have the sameproblems of conveying, weighing, but also may have the added concernsdue to their volatility and ability to flow without spillage. Forexample, a viscous liquid may require heating in order to promoterequired flow rates for accurate weighing and adding to the batchinternal mixer without the generation of volatile gas emissions.

Moreover, the further downstream processing of these uncured rubbermixes may be highly dependent upon the specific factory equipment used.Thus, properties of the uncured rubber mixes such as Mooney viscosityand Mooney scorch values can be important variables and parameters tomanage in helping to optimize manufacturing efficiency, particularlysince rubber processing equipment subsequent to mixing such as rollmills, roller dies, calendars, extruders, and the like can differsignificantly in production volumes and rates and in operatingtemperatures throughout factories throughout the world. Thus, arequirement for an ingredient for these mixes is its ability tocontribute to the ease of processing of the uncured rubber mixes. Inparticular, when fabricating that portion of the tire relied upon forair impermeability, such as the tire innerliner, manufacturers haveapplied a myriad of approaches including the widespread use of “butyl”rubbers or elastomers in various embodiments.

Butyl rubbers, generally, copolymers of isobutylene and isoprene,optionally halogenated, have widespread application due to their abilityto impart desirable air impermeability properties for the tire.Halobutyl rubbers (halogenated butyl rubber) are the polymers of choicefor air-retention in tire innerliners for passenger, truck/bus, andaircraft applications. See, for example, U.S. Pat. No. 5,922,153, U.S.Pat. No. 5,491,196, EP 0 102 844 and EP 0 127 998. Bromobutyl rubber,chlorobutyl rubbers, and branched (“star-branched”) halogenated butylrubbers are isobutylene-based elastomers that can be formulated forthese specific applications. EXXPRO™ elastomers (ExxonMobil ChemicalCompany, Houston, Tex.), generally, halogenated random copolymers ofisobutylene and para-methylstyrene, have also been of particularinterest due to their improvements over traditional butyl rubbers. See,for example, U.S. Pat. No. 6,293,327, U.S. Pat. No. 5,386,864, U.S.Patent Application Publication No. 2002/151636, JP 2003170438, and JP2003192854 (applying various approaches of blends of commercial EXXPRO™elastomers with other polymers).

Of the myriad of choices an artisan has in processing the aforementionedelastomeric compositions, selection of the processing aid is of growingimportance. Processing aids are an important consideration whenprocessing elastomers for tire innerliners because they can affect thepermeability of the cured tire, the ability of the components of theshaped but uncured tire to adhere to one another called “green tack,”and/or the downstream processing efficiency of the uncured rubber mixes.By selecting the appropriate processing aid, a manufacturer can effectthe conditions by which the elastomers are processed and many of theproperties of the end use articles produced by those elastomers. Forexample, a lower Mooney viscosity uncured rubber mix may allow for anincrease in production rates. However, too low of a Mooney viscosity mayresult in the stretching or tearing of the uncured rubber mixpotentially increasing scrap rates. Similarly, an increase in the Mooneyscorch of the uncured rubber mix may allow the use of higher operatingtemperatures of mills, dies, calendars, extruders, and the like.

In the past, industry generally accepted distillate “cuts” from therefining process or processing oils such as aromatic, paraffinic,naphthenic oils, and mixtures thereof to assist in the processing ofelastomeric compositions. See, for example, U.S. Pat. No. 5,162,409 andU.S. Pat. No. 5,631,316. However, use of these ingredients may result inincreasing the permeability of the air membrane such as the innerliner.More recently, polybutene processing aids have been of great interestbecause of their ability to reduce the permeability of the air membranecomponent while maintaining the other desirable properties of anin-service tire and/or in tire manufacturing. See, for example, U.S.Pat. No. 6,710,116, U.S. Patent Application Publication No.2005/0027062, WO 2002/32995, WO 2002/32992, WO 2002/32993, WO2002/48257, and WO 2004/009700. The use of polybutene processing aidsrepresents a radical departure from past endeavors because theseprocessing aids are produced through polymerization processes notdistillate “cuts” from the refining process.

Other background references include WO 2004/058874 and JP 2003292705.

However, even more improvements are needed to provide more options andflexibility to the balance of properties that manufacturers mustconsider when making decisions on how elastomers should be processed inlight of the desired properties of the specific end use articles. Forexample, it is still desirable to further reduce the permeability of theair membrane component of a tire or to maintain the permeability of theair membrane component and/or reduce the processing restrictions of theuncured rubber mixes. The present invention fulfills this need byproviding more options in this regard through the use of processing aidsincluding functionalized polymers described herein.

SUMMARY OF THE INVENTION

The invention provides for processes to produce elastomericcompositions, the processes comprising contacting at least one elastomerwith a processing aid, wherein the processing aid comprises at least onefunctionalized polymer having at least one anhydride group.

In another embodiment, the invention also provides for articles such asinnerliners for tires produced from the aforementioned elastomericcompositions.

DETAILED DESCRIPTION OF THE INVENTION

Various specific embodiments, versions and examples of the inventionwill now be described, including preferred embodiments and definitionsthat are adopted herein for purposes of understanding the claimedinvention.

In reference to Periodic Table “Groups”, the new numbering scheme forthe Periodic Table Groups is used as found in HAWLEY'S CONDENSEDCHEMICAL DICTIONARY, P 852 (13th ed. 1997).

Slurry refers to a volume of diluent comprising polymers that haveprecipitated from the diluent, monomers, Lewis acid, and initiator. Theslurry concentration is the volume percent of the partially orcompletely precipitated polymers based on the total volume of theslurry.

Polymer may be used to refer to homopolymers, copolymers, interpolymers,terpolymers, etc. Likewise, a copolymer may refer to a polymercomprising at least two monomers, optionally with other monomers.

When a polymer is referred to as comprising a monomer, the monomer ispresent in the polymer in the polymerized form of the monomer or in thederivative form the monomer. However, for ease of reference the phrasecomprising the (respective) monomer or the like is used as shorthand.Likewise, when catalyst components are described as comprising neutralstable forms of the components, it is well understood by one skilled inthe art, that the ionic form of the component is the form that reactswith the monomers to produce polymers.

Rubber refers to any polymer or composition of polymers consistent withthe ASTM D1566 definition: “a material that is capable of recoveringfrom large deformations, and can be, or already is, modified to a statein which it is essentially insoluble (but can swell) in boilingsolvent.”. Elastomer is a term that may be used interchangeably with theterm rubber.

Elastomeric composition refers to any composition comprising at leastone elastomer as defined above.

A vulcanized rubber compound by ASTM D1566 definition refers to “acrosslinked elastic material compounded from an elastomer, susceptibleto large deformations by a small force capable of rapid, forcefulrecovery to approximately its original dimensions and shape upon removalof the deforming force”. A cured elastomeric composition refers to anyelastomeric composition that has undergone a curing process and/orcomprises or is produced using an effective amount of a curative or curepackage, and is a term used interchangeably with the term vulcanizedrubber compound.

A thermoplastic elastomer by ASTM D1566 definition refers to arubber-like material “that repeatedly can be softened by heating andhardened by cooling through a temperature range characteristic of thepolymer, and in the softened state can be shaped into articles”.Thermoplastic elastomers are microphase separated systems of at leasttwo polymers. One phase is the hard polymer that does not flow at roomtemperature, but becomes fluid when heated, that gives thermoplasticelastomers its strength. The other phase is a soft rubbery polymer thatgives thermoplastic elastomers their elasticity. The hard phase istypically the major or continuous phase.

A thermoplastic vulcanizate by ASTM D1566 definition refers to “athermoplastic elastomer with a chemically cross-linked rubbery phase,produced by dynamic vulcanization”. Dynamic vulcanization is “theprocess of intimate melt mixing of a thermoplastic polymer and asuitable reactive rubbery polymer to generate a thermoplastic elastomerwith a chemically cross-linked rubbery phase . . . ”. The rubbery phase,whether or not cross-linked, is typically the minor or dispersed phase.

The term “phr” is parts per hundred rubber or “parts”, and is a measurecommon in the art wherein components of a composition are measuredrelative to a total of all of the elastomer components. The total phr orparts for all rubber components, whether one, two, three, or moredifferent rubber components is present in a given recipe is alwaysdefined as 100 phr. All other non-rubber components are ratioed againstthe 100 parts of rubber and are expressed in phr. This way one caneasily compare, for example, the levels of curatives or filler loadings,etc., between different compositions based on the same relativeproportion of rubber without the need to recalculate percents for everycomponent after adjusting levels of only one, or more, component(s).

Isoolefin refers to any olefin monomer having at least one carbon havingtwo substitutions on that carbon.

Multiolefin refers to any monomer having two or more double bonds. In apreferred embodiment, the multiolefin is any monomer comprising twoconjugated double bonds such as a conjugated diene like isoprene.

Isobutylene based elastomer or polymer refers to elastomers or polymerscomprising at least 70 mol % repeat units from isobutylene.

Hydrocarbon refers to molecules or segments of molecules containingprimarily hydrogen and carbon atoms. In some embodiments, hydrocarbonalso includes halogenated versions of hydrocarbons and versionscontaining heteroatoms as discussed in more detail below.

Alkyl refers to a paraffinic hydrocarbon group which may be derived froman alkane by dropping one or more hydrogens from the formula, such as,for example, a methyl group (CH₃), or an ethyl group (CH₃CH₂), etc.

Aryl refers to a hydrocarbon group that forms a ring structurecharacteristic of aromatic compounds such as, for example, benzene,naphthalene, phenanthrene, anthracene, etc., and typically possessalternate double bonding (“unsaturation”) within its structure. An arylgroup is thus a group derived from an aromatic compound by dropping oneor more hydrogens from the formula such as, for example, a phenyl group(C₆H₅).

Substituted refers to at least one hydrogen group being replaced by atleast one substituent selected from, for example, halogen (chlorine,bromine, fluorine, or iodine), amino, nitro, sulfoxy (sulfonate or alkylsulfonate), thiol, alkylthiol, and hydroxy; alkyl, straight or branchedchain having 1 to 20 carbon atoms which includes methyl, ethyl, propyl,isopropyl, normal butyl, isobutyl, secondary butyl, tertiary butyl,etc.; alkoxy, straight or branched chain alkoxy having 1 to 20 carbonatoms, and includes, for example, methoxy, ethoxy, propoxy, isopropoxy,butoxy, isobutoxy, secondary butoxy, tertiary butoxy, pentyloxy,isopentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, and decyloxy;haloalkyl, which means straight or branched chain alkyl having 1 to 20carbon atoms which is substituted by at least one halogen, and includes,for example, chloromethyl, bromomethyl, fluoromethyl, iodomethyl,2-chloroethyl, 2-bromoethyl, 2-fluoroethyl, 3-chloropropyl,3-bromopropyl, 3-fluoropropyl, 4-chlorobutyl, 4-fluorobutyl,dichloromethyl, dibromomethyl, difluoromethyl, diiodomethyl,2,2-dichloroethyl, 2,2-dibromoethyl, 2,2-difluoroethyl,3,3-dichloropropyl, 3,3-difluoropropyl, 4,4-dichlorobutyl,4,4-dibromobutyl, 4,4-difluorobutyl, trichloromethyl, trifluoromethyl,2,2,2-trifluoroethyl, 2,3,3-trifluoropropyl, 1,1,2,2-tetrafluoroethyl,and 2,2,3,3-tetrafluoropropyl. Thus, for example, a “substitutedstyrenic unit” includes p-methylstyrene, p-ethylstyrene, etc.

Butyl Rubber

Preferred elastomers useful in the practice of this invention includeisobutylene-based homopolymers or copolymers. As stated above, anisobutylene based elastomer or a polymer refers to an elastomer or apolymer comprising at least 70 mol % repeat units from isobutylene.These polymers can be described as random copolymer of a C₄ to C₇isomonoolefin derived unit, such as isobutylene derived unit, and atleast one other polymerizable unit. The isobutylene-based copolymer mayor may not be halogenated.

In one embodiment of the invention, the elastomer is a butyl-type rubberor branched butyl-type rubber, especially halogenated versions of theseelastomers. Useful elastomers are unsaturated butyl rubbers such ashomopolymers and copolymers of olefins or isoolefins and multiolefins,or homopolymers of multiolefins. These and other types of elastomerssuitable for the invention are well known and are described in RUBBERTECHNOLOGY, P 209-581 (Morton ed., Chapman & Hall 1995), THE VANDERBILTRUBBER HANDBOOK, P 105-122 (Ohm ed., R.T. Vanderbilt Co., Inc. 1990),and Kresge and Wang in 8 KIRK-OTHMER ENCYCLOPEDIA OF CHEMICALTECHNOLOGY, P 934-955 (John Wiley & Sons, Inc. 4th ed. 1993).Non-limiting examples of unsaturated elastomers useful in the method andcomposition of the present invention are poly(isobutylene-co-isoprene),polyisoprene, polybutadiene, polyisobutylene,poly(styrene-co-butadiene), natural rubber, star-branched butyl rubber,and mixtures thereof. Useful elastomers in the present invention can bemade by any suitable means known in the art, and the invention is notherein limited by the method of producing the elastomer.

Elastomeric compositions may comprise at least one butyl rubber. Butylrubbers are prepared by reacting a mixture of monomers, the mixturehaving at least (1) a C₄ to C₇ isoolefin monomer component such asisobutylene with (2) a multiolefin, monomer component. The isoolefin isin a range from 70 to 99.5 wt % by weight of the total monomer mixturein one embodiment, and 85 to 99.5 wt % in another embodiment. Themultiolefin component is present in the monomer mixture from 30 to 0.5wt % in one embodiment, and from 15 to 0.5 wt % in another embodiment.In yet another embodiment, from 8 to 0.5 wt % of the monomer mixture ismultiolefin.

The isoolefin is a C₄ to C₇ compound, non-limiting examples of which arecompounds such as isobutylene, isobutene, 2-methyl-1-butene,3-methyl-1-butene, 2-methyl-2-butene, 1-butene, 2-butene, methyl vinylether, indene, vinyltrimethylsilane, hexene, and 4-methyl-1-pentene. Themultiolefin is a C₄ to C₁₄ multiolefin such as isoprene, butadiene,2,3-dimethyl-1,3-butadiene, myrcene, 6,6-dimethyl-fulvene, hexadiene,cyclopentadiene, and piperylene, and other monomers such as disclosed inEP 0 279 456, U.S. Pat. No. 5,506,316 and U.S. Pat. No. 5,162,425. Otherpolymerizable monomers such as styrene and dichlorostyrene are alsosuitable for homopolymerization or copolymerization in butyl rubbers.One embodiment of the butyl rubber polymer of the invention is obtainedby reacting 95 to 99.5 wt % of isobutylene with 0.5 to 8 wt % isoprene,or from 0.5 wt % to 5.0 wt % isoprene in yet another embodiment. Butylrubbers and methods of their production are described in detail in, forexample, U.S. Pat. No. 2,356,128, U.S. Pat. No. 3,968,076, U.S. Pat. No.4,474,924, U.S. Pat. No. 4,068,051 and U.S. Pat. No. 5,532,312. See,also, WO 2004/058828, WO 2004/058827, WO 2004/058835, WO 2004/058836, WO2004/058825, WO 2004/067577, and WO 2004/058829.

A commercial example of a desirable butyl rubber is EXXON™ BUTYL Gradesof poly(isobutylene-co-isoprene), having a Mooney viscosity of from 30to 56 (ML 1+8 at 125° C.) (ExxonMobil Chemical Company, Houston, Tex.).Another commercial example of a desirable butyl-type rubber is VISTANEX™polyisobutylene rubber having a molecular weight viscosity average offrom 0.75 to 2.34×10⁶ (ExxonMobil Chemical Company, Houston, Tex.).

Star Branched Butyl Rubber

Another embodiment of the butyl rubber useful in the invention is abranched or “star-branched” butyl rubber. These rubbers are describedin, for example, EP 0 678 529 B1, U.S. Pat. No. 5,182,333 and U.S. Pat.No. 5,071,913. In one embodiment, the star-branched butyl rubber (“SBB”)is a composition of a butyl rubber, either halogenated or not, and apolydiene or block copolymer, either halogenated or not. The inventionis not limited by the method of forming the SBB. The polydienes/blockcopolymer, or branching agents (hereinafter “polydienes”), are typicallycationically reactive and are present during the polymerization of thebutyl or halogenated butyl rubber, or can be blended with the butylrubber to form the SBB. The branching agent or polydiene can be anysuitable branching agent, and the invention is not limited to the typeof polydiene used to make the SBB.

In one embodiment, the SBB is typically a composition of the butyl orhalogenated butyl rubber as described above and a copolymer of apolydiene and a partially hydrogenated polydiene selected from the groupincluding styrene, polybutadiene, polyisoprene, polypiperylene, naturalrubber, styrene-butadiene rubber, ethylene-propylene diene rubber(EPDM), ethylene-propylene rubber (EPR), styrene-butadiene-styrene andstyrene-isoprene-styrene block copolymers. These polydienes are present,based on the monomer wt %, greater than 0.3 wt % in one embodiment, andfrom 0.3 to 3 wt % in another embodiment, and from 0.4 to 2.7 wt % inyet another embodiment.

A commercial embodiment of the SBB of the present invention is SB Butyl4266 (ExxonMobil Chemical Company, Houston, Tex.), having a Mooneyviscosity (ML 1+8 at 125° C., ASTM D 1646) of from 34 to 44. Further,cure characteristics of SB Butyl 4266 are as follows: MH is 69±6 dN·m,ML is 11.5±4.5 dN·m (ASTM D2084).

Halogenated Butyl Rubber

The elastomer in a desirable embodiment of the invention is halogenated.Halogenated butyl rubber is produced by the halogenation of the butylrubber product described above. Halogenation can be carried out by anymeans, and the invention is not herein limited by the halogenationprocess. Methods of halogenating polymers such as butyl polymers aredisclosed in U.S. Pat. No. 2,631,984, U.S. Pat. No. 3,099,644, U.S. Pat.No. 4,554,326, U.S. Pat. No. 4,681,921, U.S. Pat. No. 4,650,831, U.S.Pat. No. 4,384,072, U.S. Pat. No. 4,513,116 and U.S. Pat. No. 5,681,901.In one embodiment, the butyl rubber is halogenated in hexane diluent atfrom 4 to 60° C. using bromine (Br₂) or chlorine (Cl₂) as thehalogenation agent. The halogenated butyl rubber has a Mooney Viscosityof from 20 to 70 (ML 1+8 at 125° C.) in one embodiment, and from 25 to55 in another embodiment. The halogen wt % is from 0.1 to 10 wt % basedin on the weight of the halogenated butyl rubber in one embodiment, andfrom 0.5 to 5 wt % in another embodiment. In yet another embodiment, thehalogen wt % of the halogenated butyl rubber is from 1 to 2.5 wt %.

A commercial embodiment of a suitable halogenated butyl rubber of thepresent invention is Bromobutyl 2222 (ExxonMobil Chemical Company,Houston, Tex.). Its Mooney viscosity is from 27 to 37 (ML 1+8 at 125°C., ASTM 1646, modified), and the bromine content is from 1.8 to 2.2 wt% relative to the Bromobutyl 2222. Further, cure characteristics ofBromobutyl 2222 are as follows: MH is from 28 to 40 dN·m, ML is from 7to 18 dN·m (ASTM D2084). Another commercial embodiment of thehalogenated butyl rubber is Bromobutyl 2255 (ExxonMobil ChemicalCompany, Houston, Tex.). Its Mooney viscosity is from 41 to 51 (ML 1+8at 125° C., ASTM D1646), and the bromine content is from 1.8 to 2.2 wt%. Further, cure characteristics of Bromobutyl 2255 are as follows: MHis from 34 to 48 dN·m, ML is from 11 to 21 dN·m (ASTM D2084).

Star Branched Halogenated Butyl Rubber

In another embodiment of elastomer of the invention, a branched or“star-branched” halogenated butyl rubber is used. In one embodiment, thehalogenated star-branched butyl rubber is a composition of a butylrubber, either halogenated or not, and a polydiene or block copolymer,either halogenated or not. The halogenation process is described indetail in U.S. Pat. No. 4,074,035, U.S. Pat. No. 5,071,913, U.S. Pat.No. 5,286,804, U.S. Pat. No. 5,182,333 and U.S. Pat. No. 6,228,978. Theinvention is not limited by the method of forming the halogenated starbranched butyl rubber. The polydienes/block copolymer, or branchingagents (hereinafter “polydienes”), are typically cationically reactiveand are present during the polymerization of the butyl or halogenatedbutyl rubber, or can be blended with the butyl or halogenated butylrubber to form the halogenated star branched butyl rubber. The branchingagent or polydiene can be any suitable branching agent, and theinvention is not limited to the type of polydiene used to make thehalogenated star branched butyl rubber.

In one embodiment, the halogenated star branched butyl rubber istypically a composition of the butyl or halogenated butyl rubber asdescribed above and a copolymer of a polydiene and a partiallyhydrogenated polydiene selected from the group including styrene,polybutadiene, polyisoprene, polypiperylene, natural rubber,styrene-butadiene rubber, ethylene-propylene diene rubber,styrene-butadiene-styrene and styrene-isoprene-styrene block copolymers.These polydienes are present, based on the monomer wt %, greater than0.3 wt % in one embodiment, and from 0.3 to 3 wt % in anotherembodiment, and from 0.4 to 2.7 wt % in yet another embodiment.

A commercial embodiment of the halogenated star branched butyl rubber ofthe present invention is Bromobutyl 6222 (ExxonMobil Chemical Company,Houston, Tex.), having a Mooney viscosity (ML 1+8 at 125° C., ASTMD1646) of from 27 to 37, and a bromine content of from 2.2 to 2.6 wt %relative to the halogenated star branched butyl rubber. Further, curecharacteristics of Bromobutyl 6222 are as follows: MH is from 24 to 38dN·m, ML is from 6 to 16 dN·m (ASTM D2084).

Halogenated Isobutylene-Para-Methylstyrene Rubber

Elastomeric compositions of the present invention may also comprise atleast one random copolymer comprising a C₄ to C₇ isomonoolefins, such asisobutylene and an alkylstyrene comonomer, such as para-methylstyrene,containing at least 80%, more alternatively at least 90% by weight ofthe para-isomer and optionally include functionalized interpolymerswherein at least one or more of the alkyl substituents groups present inthe styrene monomer units contain benzylic halogen or some otherfunctional group. In another embodiment, the polymer may be a randomelastomeric copolymer of ethylene or a C₃ to C₆ a-olefin and analkylstyrene comonomer, such as para-methylstyrene containing at least80%, alternatively at least 90% by weight of the para-isomer andoptionally include functionalized interpolymers wherein at least one ormore of the alkyl substituents groups present in the styrene monomerunits contain benzylic halogen or some other functional group. Exemplarymaterials may be characterized as polymers containing the followingmonomer units randomly spaced along the polymer chain:

wherein R and R¹ are independently hydrogen, lower alkyl, such as a C₁to C₇ alkyl and primary or secondary alkyl halides and X is a functionalgroup such as halogen. In an embodiment, R and R¹ are each hydrogen. Upto 60 mol % of the para-substituted styrene present in the randompolymer structure may be the functionalized structure (2) above in oneembodiment, and in another embodiment from 0.1 to 5 mol %. In yetanother embodiment, the amount of functionalized structure (2) is from0.2 to 3 mol %.

The functional group X may be halogen or some other functional groupwhich may be incorporated by nucleophilic substitution of benzylichalogen with other groups such as carboxylic acids; carboxy salts;carboxy esters, amides and imides; hydroxy; alkoxide; phenoxide;thiolate; thioether; xanthate; cyanide; cyanate; amino and mixturesthereof. These functionalized isomonoolefin copolymers, their method ofpreparation, methods of functionalization, and cure are moreparticularly disclosed in U.S. Pat. No. 5,162,445.

In an embodiment, the elastomer comprises random polymers of isobutyleneand para-methylstyrene containing from 0.5 to 20 mol %para-methylstyrene wherein up to 60 mol % of the methyl substituentgroups present on the benzyl ring contain a bromine or chlorine atom,such as a bromine atom (para-(bromomethylstyrene)), as well as acid orester functionalized versions thereof.

In another embodiment, the functionality is selected such that it canreact or form polar bonds with functional groups present in the matrixpolymer, for example, acid, amino or hydroxyl functional groups, whenthe polymer components are mixed at high temperatures.

In certain embodiments, the random copolymers have a substantiallyhomogeneous compositional distribution such that at least 95 wt % of thepolymer has a para-alkylstyrene content within 10% of the averagepara-alkylstyrene content of the polymer. Exemplary polymers arecharacterized by a narrow molecular weight distribution (Mw/Mn) of lessthan 5, alternatively less than 2.5, an exemplary viscosity averagemolecular weight in the range of from 200,000 up to 2,000,000 and anexemplary number average molecular weight in the range of from 25,000 to750,000 as determined by gel permeation chromatography.

In an embodiment, brominated poly(isobutylene-co-p-methylstyrene)polymers generally contain from 0.1 to 5 mol % of bromomethylstyrenegroups relative to the total amount of monomer derived units in thecopolymer. In another embodiment, the amount of bromomethyl groups isfrom 0.2 to 3.0 mol %, and from 0.3 to 2.8 mol % in yet anotherembodiment, and from 0.4 to 2.5 mol % in yet another embodiment, andfrom 0.3 to 2.0 mol % in yet another embodiment, wherein a desirablerange may be any combination of any upper limit with any lower limit.Expressed another way, exemplary copolymers contain from 0.2 to 10 wt %of bromine, based on the weight of the polymer, from 0.4 to 6 wt %bromine in another embodiment, and from 0.6 to 5.6 wt % in anotherembodiment, are substantially free of ring halogen or halogen in thepolymer backbone chain. In one embodiment, the random polymer is acopolymer of C₄ to C₇ isoolefin derived units (or isomonoolefin),para-methylstyrene derived units and para-(halomethylstyrene) derivedunits, wherein the para-(halomethylstyrene) units are present in thepolymer from 0.4 to 3.0 mol % based on the total number ofpara-methylstyrene, and wherein the para-methylstyrene derived units arepresent from 3 to 15 wt % based on the total weight of the polymer inone embodiment, and from 4 to 10 wt % in another embodiment. In anotherembodiment, the para-(halomethylstyrene) is para-(bromomethylstyrene).

A commercial embodiment of the halogenated isobutylene-p-methylstyrenerubber of the present invention is EXXPRO™ elastomers (ExxonMobilChemical Company, Houston, Tex.), having a Mooney viscosity (ML 1+8 at125° C., ASTM D1646) of from 30 to 50, a p-methylstyrene content of from4 to 8.5 wt %, and a bromine content of from 0.7 to 2.2 wt % relative tothe halogenated isobutylene-p-methylstyrene rubber.

The elastomer(s) such as discussed above may be prepared by a slurrypolymerization, typically in a diluent comprising a halogenatedhydrocarbon(s) such as a chlorinated hydrocarbon and/or a fluorinatedhydrocarbon including mixtures thereof, (see e.g., WO 2004/058828, WO2004/058827, WO 2004/058835, WO 2004/058836, WO 2004/058825, WO2004/067577, and WO 2004/058829).

In certain embodiments directed to blends, the elastomer(s) as describedabove may be combined with at least one of the following.

General Purpose Rubber

A general purpose rubber, often referred to as a commodity rubber, maybe any rubber that usually provides high strength and good abrasionalong with low hysteresis and high resilience. These elastomers requireantidegradants in the mixed compound because they generally have poorresistance to both heat and oxygen, in particular to ozone. They areoften easily recognized in the market because of their low sellingprices relative to specialty elastomers and their big volumes of usageas described by School in RUBBER TECHNOLOGY COMPOUNDING AND TESTING FORPERFORMANCE, p 125 (Dick, ed., Hanser, 2001).

Examples of general purpose rubbers include natural rubbers (NR),polyisoprene rubber (IR), poly(styrene-co-butadiene) rubber (SBR),polybutadiene rubber (BR), poly(isoprene-co-butadiene) rubber (IBR), andstyrene-isoprene-butadiene rubber (SIBR), and mixtures thereof.Ethylene-propylene rubber (EPM) and ethylene-propylene-diene rubber(EPDM), and their mixtures, often are also referred to as generalpurpose elastomers.

In another embodiment, the composition may also comprise a naturalrubber. Natural rubbers are described in detail by Subramaniam in RUBBERTECHNOLOGY, p 179-208 (Morton, ed., Chapman & Hall, 1995). Desirableembodiments of the natural rubbers of the present invention are selectedfrom Malaysian rubber such as SMR CV, SMR 5, SMR 10, SMR 20, and SMR 50and mixtures thereof, wherein the natural rubbers have a Mooneyviscosity as measured at 100° C. (ML 1+4) of from 30 to 120, morepreferably from 40 to 65. The Mooney viscosity test referred to hereinis in accordance with ASTM D1646.

In another embodiment, the elastomeric composition may also comprise apolybutadiene rubber (BR). The Mooney viscosity of the polybutadienerubber as measured at 100° C. (ML 1+4) may range from 35 to 70, from 40to about 65 in another embodiment, and from 45 to 60 in yet anotherembodiment. Commercial examples of these synthetic rubbers useful in thepresent invention are sold under the trade name BUDENE™ (GoodyearChemical Company, Akron, Ohio), BUNA™ (Lanxess Inc., Sarnia, Ontario,Canada), and Diene™ (Firestone Polymers LLC, Akron, Ohio). An example ishigh cis-polybutadiene (cis-BR). By “cis-polybutadiene” or “highcis-polybutadiene”, it is meant that 1,4-cis polybutadiene is used,wherein the amount of cis component is at least 95%. A particularexample of high cis-polybutadiene commercial products used in thecomposition BUDENE™ 1207 or BUNA™ CB 23.

In another embodiment, the elastomeric composition may also comprise apolyisoprene rubber (IR). The Mooney viscosity of the polyisoprenerubber as measured at 100° C. (ML 1+4) may range from 35 to 70, from 40to about 65 in another embodiment, and from 45 to 60 in yet anotherembodiment. A commercial example of these synthetic rubbers useful inthe present invention is NATSYN™ 2200 (Goodyear Chemical Company, Akron,Ohio).

In another embodiment, the elastomeric composition may also compriserubbers of ethylene and propylene derived units such as EPM and EPDM assuitable additional rubbers. Examples of suitable comonomers in makingEPDM are ethylidene norbornene, 1,4-hexadiene, dicyclopentadiene, aswell as others. These rubbers are described in RUBBER TECHNOLOGY, P260-283 (1995). A suitable ethylene-propylene rubber is commerciallyavailable as VISTALON™ (ExxonMobil Chemical Company, Houston, Tex.).

In yet another embodiment, the elastomeric composition may comprise aterpolymer of ethylene/alpha-olefin/diene terpolymer. The alpha-olefinis selected from the group consisting of C₃ to C₂₀ alpha-olefin withpropylene, butene and octene preferred and propylene most preferred. Thediene component is selected from the group consisting of C₄ to C₂₀dienes. Examples of suitable dienes include straight chain, hydrocarbondiolefin or cylcloalkenyl-substituted alkenes having from 6 to 15 carbonatoms. Specific examples include (a) straight chain acyclic dienes suchas 1,4-hexadiene and 1,6-octadiene; (b) branched chain acyclic dienessuch as 5-methyl-1,4-hexadiene; 3,7-dimethyl-1,6-octadiene;3,7-dimethyl-1,7-octadiene; and the mixed isomers of dihydromyricene anddihydroocinene; (c) single ring alicyclic dienes, such as 1,3cyclopentadiene; 1,4-cyclohexadiene; 1,5-cyclooctadiene and1,5-cyclododecadiene; (d) multi-ring alicyclic fused and bridged ringdienes such as tetrahydroindene; methyl-tetrahydroindene;dicyclopentadiene (DCPD); bicyclo-(2.2.1)-hepta-2,5-diene; alkenyl,alkylidene, cycloalkenyl and cycloalkylidene norbornene, such as5-methylene-2-norbornene (MNB), 5-propenyl-2-norbornene,5-isopropylidene-2-norbornene, 5-ethylidene-2-norbornene (ENB),5-(4-cyclopentenyl)-2-norbornene, 5-cyclohexylidene-2-norbornene, and5-vinyl-2-norbornene (VNB); (e) cycloalkenyl-substituted alkenes, suchas allyl cyclohexene, vinyl cyclooctene, allyl cyclodecene, vinylcyclododecene. Examples also include dicyclopentadiene, 1,4-hexadiene,5-methylene-2-norbornene, and 5-ethylidene-2-norbornene. Examples ofdiolefins are 5-ethylidene-2-norbornene; 1,4-hexadiene,dicyclopentadiene and 5-vinyl-2-norbornene. For more information and anexample how an artisan might apply these terpolymer, see, for example,U.S. Pat. No. 6,245,856.

Specialty Rubber

In one embodiment, the secondary elastomer is a specialty rubbercontaining a polar functional group such as butadiene-acrylonitrilerubber (NBR, or nitrile rubber), a copolymer of 2-propenenitrile and1,3-butadiene. Nitrile rubber can have an acrylonitrile content of from10 to 50 wt % in one embodiment, from 15 to 40 wt % in anotherembodiment, and from 18 to 35 wt % in yet another embodiment. The Mooneyviscosity may range from 30 to 90 in one embodiment (1+4, 100° C., ASTMD1646), and from 30 to 75 in another embodiment. These rubbers arecommon in the art, and described in, for example, HANDBOOK OF PLASTICS,ELASTOMERS, AND COMPOSITES 1.41-1.49 (Harper, ed., McGraw-Hill, Inc.1992). Commercial examples of these synthetic rubbers useful in thepresent invention are sold under the trade names BREON™, NIPOL™, SIVIC™and ZETPOL™ (Zeon Chemicals, Louisville, Ky.), EUROPRENE™ N (PolimeriEuropa Americas, Houston, Tex.), and KRYNAC™, PERBUNAN™ and THERBAN™(Lanxess Corporation, Akron, Ohio).

In another embodiment, the secondary elastomer is a derivative of NBRsuch as hydrogenated or carboxylated or styrenated nitrile rubbers.Butadiene-acrylonitrile-styrene rubber (SNBR, or “ABS” rubber), acopolymer of 2-propenenitrile, 1,3-butadiene and styrene, can have anacrylonitrile content of from 10 to 40 wt % in one embodiment, from 15to 30 wt % in another embodiment, and from 18 to 30 wt % in yet anotherembodiment. The styrene content of the SNBR copolymer may range from 15to 40 wt % in one embodiment, and from 18 to 30 wt % in anotherembodiment, and from 20 to 25 wt % in yet another embodiment. The Mooneyviscosity may range from 30 to 60 in one embodiment (1+4, 100° C., ASTMD1646), and from 30 to 55 in another embodiment. These rubbers arecommon in the art, and described in, for example, HANDBOOK OF PLASTICS,ELASTOMERS, AND COMPOSITES 1.41-1.49 (Harper, ed., McGraw-Hill, Inc.1992). A commercial example of this synthetic rubber useful in thepresent invention is sold under the trade name KRYNAC™ (LanxessCorporation, Akron, Ohio).

In yet another embodiment, the secondary elastomer is a specialty rubbercontaining a halogen group such as polychloroprene (CR, or chloroprenerubber), a homopolymer of 2-chloro-1,3-butadiene. The Mooney viscositymay range from 30 to 110 in one embodiment (1+4, 100° C., ASTM D1646),and from 35 to 75 in another embodiment. These rubbers are common in theart, and described in, for example, HANDBOOK OF PLASTICS, ELASTOMERS,AND COMPOSITES 1.41-1.49 (Harper, ed., McGraw-Hill, Inc. 1992).Commercial examples of these synthetic rubbers useful in the presentinvention are sold under the trade names NEOPRENE™ (DuPont DowElastomers, Wilmington, Del.), BUTACLOR™ (Polimeri Europa Americas,Houston, Tex.) and BAYPREN™ (Lanxess Corporation, Akron, Ohio).

Semicrystalline Polymer

In an embodiment, the elastomeric compositions may comprise at least onesemicrystalline polymer that is an elastic polymer with a moderate levelof crystallinity due to stereoregular propylene sequences. Thesemicrystalline polymer may comprise: (A) a propylene homopolymer inwhich the stereoregularity is disrupted in some manner such as byregio-inversions; (B) a random propylene copolymer in which thepropylene stereoregularity is disrupted at least in part by comonomersor (C) a combination of (A) and (B).

In another embodiment, the semicrystalline polymer further comprises anon-conjugated diene monomer to aid in vulcanization and other chemicalmodification of the blend composition. The amount of diene present inthe polymer is preferably less than 10 wt %, and more preferably lessthan 5 wt %. The diene may be any non-conjugated diene which is commonlyused for the vulcanization of ethylene propylene rubbers including, butnot limited to, ethylidene norbornene, vinyl norbornene, anddicyclopentadiene.

In one embodiment, the semicrystalline polymer is a random copolymer ofpropylene and at least one comonomer selected from ethylene, C₄-C₁₂α-olefins, and combinations thereof. In a particular aspect of thisembodiment, the copolymer includes ethylene-derived units in an amountranging from a lower limit of 2 wt %, 5 wt %, 6 wt %, 8 wt %, or 10 wt %to an upper limit of 20 wt %, 25 wt %, or 28 wt %. This embodiment mayalso include propylene-derived units present in the copolymer in anamount ranging from a lower limit of 72 wt %, 75 wt %, or 80 wt % to anupper limit of 98 wt %, 95 wt %, 94 wt %, 92 wt %, or 90 wt %. Thesepercentages by weight are based on the total weight of the propylene andethylene-derived units; i.e., based on the sum of weight percentpropylene-derived units and weight percent ethylene-derived units being100%.

The ethylene composition of a polymer can be measured as follows. A thinhomogeneous film is pressed at a temperature of about 150° C. orgreater, then mounted on a Perkin Elmer PE 1760 infraredspectrophotometer. A full spectrum of the sample from 600 cm⁻¹ to 4000cm⁻¹ is recorded and the monomer weight percent of ethylene can becalculated according to the following equation: Ethylene wt%=82.585−111.987X+30.045 X², wherein X is the ratio of the peak heightat 1155 cm⁻¹ and peak height at either 722 cm⁻¹ or 732 cm⁻¹, whicheveris higher. The concentrations of other monomers in the polymer can alsobe measured using this method.

Comonomer content of discrete molecular weight ranges can be measured byFourier Transform Infrared Spectroscopy (FTIR) in conjunction withsamples collected by GPC. One such method is described in Wheeler andWillis, Applied Spectroscopy, vol 47, p 1128-1130 (1993). Different butsimilar methods are equally functional for this purpose and well knownto those skilled in the art.

Comonomer content and sequence distribution of the polymers can bemeasured by ¹³C nuclear magnetic resonance spectroscopy (¹³C NMR), andsuch method is well known to those skilled in the art.

In one embodiment, the semicrystalline polymer comprises a randompropylene copolymer having a narrow compositional distribution. Inanother embodiment, the polymer is a random propylene copolymer having anarrow compositional distribution and a melting point as determined byDSC of from 25° C. to 110° C. The copolymer is described as randombecause for a polymer comprising propylene, comonomer, and optionallydiene, the number and distribution of comonomer residues is consistentwith the random statistical polymerization of the monomers. Instereoblock structures, the number of block monomer residues of any onekind adjacent to one another is greater than predicted from astatistical distribution in random copolymers with a similarcomposition. Historical ethylene-propylene copolymers with stereoblockstructure have a distribution of ethylene residues consistent with theseblocky structures rather than a random statistical distribution of themonomer residues in the polymer. The intramolecular compositiondistribution (i.e., randomness) of the copolymer may be determined by¹³C NMR, which locates the comonomer residues in relation to theneighboring propylene residues. The intermolecular compositiondistribution of the copolymer is determined by thermal fractionation ina solvent. A typical solvent is a saturated hydrocarbon such as hexaneor heptane. The thermal fractionation procedure is described below.Typically, approximately 75 wt %, preferably 85 wt %, of the copolymeris isolated as one or two adjacent, soluble fractions with the balanceof the copolymer in immediately preceding or succeeding fractions. Eachof these fractions has a composition (wt % comonomer such as ethylene orother α-olefin) with a difference of no greater than 20% (relative),preferably 10% (relative), of the average weight % comonomer of thecopolymer. The copolymer has a narrow compositional distribution if itmeets the fractionation test described above. To produce a copolymerhaving the desired randomness and narrow composition, it is beneficialif (1) a single sited metallocene catalyst is used which allows only asingle statistical mode of addition of the first and second monomersequences and (2) the copolymer is well-mixed in a continuous flowstirred tank polymerization reactor which allows only a singlepolymerization environment for substantially all of the polymer chainsof the copolymer.

The crystallinity of the polymers may be expressed in terms of heat offusion. Embodiments of the present invention include polymers having aheat of fusion, as determined by DSC, ranging from a lower limit of 1.0J/g, or 3.0 J/g, to an upper limit of 50 J/g, or 10 J/g. Without wishingto be bound by theory, it is believed that the polymers of embodimentsof the present invention have generally isotactic crystallizablepropylene sequences, and the above heats of fusion are believed to bedue to the melting of these crystalline segments.

The crystallinity of the polymer may also be expressed in terms ofcrystallinity percent. The thermal energy for the highest order ofpolypropylene is estimated at 189 J/g. That is, 100% crystallinity isequal to 189 J/g. Therefore, according to the aforementioned heats offusion, the polymer has a polypropylene crystallinity within the rangehaving an upper limit of 65%, 40%, 30%, 25%, or 20%, and a lower limitof 1%, 3%, 5%, 7%, or 8%.

The level of crystallinity is also reflected in the melting point. Theterm “melting point,” as used herein, is the highest peak amongprincipal and secondary melting peaks as determined by DSC, discussedabove. In one embodiment of the present invention, the polymer has asingle melting point. Typically, a sample of propylene copolymer willshow secondary melting peaks adjacent to the principal peak, which areconsidered together as a single melting point. The highest of thesepeaks is considered the melting point. The polymer preferably has amelting point by DSC ranging from an upper limit of 110° C., 100° C.,90° C., 80° C., or 70° C., to a lower limit of 0° C., 20° C., 25° C.,30° C., 35° C., 40° C., or 45° C. Typically, a sample of thealpha-olefin copolymer component will show secondary melting peaksadjacent to principal peak; these are considered together as singlemelting point. The highest of the peaks is considered the melting point.

The semicrystalline polymer may have a weight average molecular weight(Mw) within the range having an upper limit of 5,000,000 g/mol,1,000,000 g/mol, or 500,000 g/mol, and a lower limit of 10,000 g/mol,20,000 g/mol, or 80,000 g/mol, and a molecular weight distribution Mw/Mn(MWD), sometimes referred to as a “polydispersity index” (PDI), rangingfrom a lower limit of 1.5, 1.8, or 2.0 to an upper limit of 40, 20, 10,5, or 4.5. The Mw and MWD, as used herein, can be determined by avariety of methods, including those in U.S. Pat. No. 4,540,753 andreferences cited therein, or those methods found in Verstrate et al.,Macromolecules, vol 21, p 3360 (1988), the descriptions of which areincorporated by reference herein for purposes of United Statespractices.

In one embodiment, the semicrystalline polymer has a Mooney viscosity,ML(1+4)@ 125° C., of 100 or less, 75 or less, 60 or less, or 30 or less.Mooney viscosity, as used herein, can be measured as ML(1+4)@ 125° C.according to ASTM D1646.

The semicrystalline polymer used in embodiments of the present inventioncan have a tacticity index (m/r) ranging from a lower limit of 4 or 6 toan upper limit of 8, 10, or 12. The tacticity index, expressed herein asm/r, is determined by ¹³C nuclear magnetic resonance (¹³C NMR) iscalculated as defined in Cheng, Macromolecules, vol 17, p 1950 (1984).The designation “m” or “r” describes the stereochemistry of pairs ofcontiguous propylene groups, “m” referring to meso and “r” to racemic.An m/r ratio of 1.0 generally describes a syndiotactic polymer, and anm/r ratio of 2.0 an atactic material. An isotactic materialtheoretically may have a ratio approaching infinity, and many by-productatactic polymers have sufficient isotactic content to result in ratiosof greater than 50.

In one embodiment, the semicrystalline polymer has isotacticstereoregular propylene crystallinity. The term “stereoregular” as usedherein means that the predominant number, i.e. greater than 80%, of thepropylene residues in the polypropylene or in the polypropylenecontinuous phase of a blend, such as impact copolymer exclusive of anyother monomer such as ethylene, has the same 1,2 insertion and thestereochemical orientation of the pendant methyl groups is the same,either meso or racemic.

An ancillary procedure for the description of the tacticity of thepropylene units of embodiments of the current invention is the use oftriad tacticity. The triad tacticity of a polymer is the relativetacticity of a sequence of three adjacent propylene units, a chainconsisting of head to tail bonds, expressed as a binary combination of mand r sequences. It is usually expressed for copolymers of the presentinvention as the ratio of the number of units of the specified tacticityto all of the propylene triads in the copolymer.

The triad tacticity (mm fraction) of a propylene copolymer can bedetermined from a ¹³C NMR spectrum of the propylene copolymer and thefollowing formula:

${m\; m\mspace{14mu}{Fraction}} = \frac{{PPP}\left( {m\; m} \right)}{{{PPP}\left( {m\; m} \right)} + {{PPP}({mr})} + {{PPP}({rr})}}$where PPP(mm), PPP(mr) and PPP(rr) denote peak areas derived from themethyl groups of the second units in the following three propylene unitchains consisting of head-to-tail bonds:

The ¹³C NMR spectrum of the propylene copolymer is measured as describedin U.S. Pat. No. 5,504,172. The spectrum relating to the methyl carbonregion (19-23 parts per million (ppm)) can be divided into a firstregion (21.2-21.9 ppm), a second region (20.3-21.0 ppm) and a thirdregion (19.5-20.3 ppm). Each peak in the spectrum was assigned withreference to an article in Polymer, vol 30, p 1350 (1989). In the firstregion, the methyl group of the second unit in the three propylene unitchain represented by PPP (mm) resonates. In the second region, themethyl group of the second unit in the three propylene unit chainrepresented by PPP (mr) resonates, and the methyl group (PPE-methylgroup) of a propylene unit whose adjacent units are a propylene unit andan ethylene unit resonates (in the vicinity of 20.7 ppm). In the thirdregion, the methyl group of the second unit in the three propylene unitchain represented by PPP (rr) resonates, and the methyl group(EPE-methyl group) of a propylene unit whose adjacent units are ethyleneunits resonates (in the vicinity of 19.8 ppm).

The calculation of the triad tacticity is outlined in the techniquesshown in U.S. Pat. No. 5,504,172. Subtraction of the peak areas for theerror in propylene insertions (both 2,1 and 1,3) from peak areas fromthe total peak areas of the second region and the third region, the peakareas based on the 3 propylene units-chains (PPP(mr) and PPP(rr))consisting of head-to-tail bonds can be obtained. Thus, the peak areasof PPP(mm), PPP(mr) and PPP(rr) can be evaluated, and hence the triadtacticity of the propylene unit chain consisting of head-to-tail bondscan be determined.

The semicrystalline polymer may have a triad tacticity of threepropylene units, as measured by ¹³C NMR, of 75% or greater, 80% orgreater, 82% or greater, 85% or greater, or 90% or greater.

In embodiments of the present invention, the semicrystalline polymer hasa melt flow rate (MFR) of 5000 dg/min or less, alternatively, 300 dg/minor less, alternatively 200 dg/min or less, alternatively, 100 dg/min orless, alternatively, 50 dg/min or less, alternatively, 20 dg/min orless, alternatively, 10 dg/min or less, or, alternatively, 2 dg/min orless. The determination of the MFR of the polymer is according to ASTMD1238 (230° C., 2.16 kg).

In certain embodiments, the semicrystalline polymer of the presentinvention is present in the inventive blend compositions in an amountranging from a lower limit of 50 wt %, 70 wt %, 75 wt %, 80 wt %, 82 wt%, or 85 wt % based on the total weight of the composition, to an upperlimit of 99 wt %, 95 wt %, or 90 wt % based on the total weight of thecomposition.

In certain embodiments, the semicrystalline polymer used in the presentinvention is described, for example, in WO 00/69963, WO 00/01766, WO99/07788, WO 02/083753, and described in further detail as the“Propylene Olefin Copolymer” in WO 00/01745. Semicrystalline polymersare commercially available as VISTAMAXX™ specialty elastomers(ExxonMobil Chemical Company, Houston, Tex.) and VERSIFY™ elastomers(not produced from processes herein described) (Dow Chemical Company,Midland, Mich.).

Thermoplastic Resin

In another embodiment, the elastomeric compositions may comprise atleast one thermoplastic resin. Thermoplastic resins suitable forpractice of the present invention may be used singly or in combinationand are resins containing nitrogen, oxygen, halogen, sulfur or othergroups capable of interacting with an aromatic functional groups such ashalogen or acidic groups. The resins are present in the nanocompositefrom 30 to 90 wt % of the nanocomposite in one embodiment, and from 40to 80 wt % in another embodiment, and from 50 to 70 wt % in yet anotherembodiment. In yet another embodiment, the resin is present at a levelof greater than 40 wt % of the nanocomposite, and greater than 60 wt %in another embodiment.

Suitable thermoplastic resins include resins selected from the groupconsisting or polyamides, polyimides, polycarbonates, polyesters,polysulfones, polylactones, polyacetals, acrylonitrile-butadiene-styreneresins (ABS), polyphenyleneoxide (PPO), polyphenylene sulfide (PPS),polystyrene, styrene-acrylonitrile resins (SAN), styrene maleicanhydride resins (SMA), aromatic polyketones (PEEK, PED, and PEKK) andmixtures thereof.

Suitable thermoplastic polyamides (nylons) comprise crystalline orresinous, high molecular weight solid polymers including copolymers andterpolymers having recurring amide units within the polymer chain.Polyamides may be prepared by polymerization of one or more epsilonlactams such as caprolactam, pyrrolidione, lauryllactam andaminoundecanoic lactam, or amino acid, or by condensation of dibasicacids and diamines. Both fiber-forming and molding grade nylons aresuitable. Examples of such polyamides are polycaprolactam (nylon-6),polylauryllactam (nylon-12), polyhexamethyleneadipamide (nylon-6,6)polyhexamethyleneazelamide (nylon-6,9), polyhexamethylenesebacamide(nylon-6,10), polyhexamethyleneisophthalamide (nylon-6, IP) and thecondensation product of 11-amino-undecanoic acid (nylon-11). Additionalexamples of satisfactory polyamides (especially those having a softeningpoint below 275° C.) are described in 16 ENCYCLOPEDIA OF CHEMICALTECHNOLOGY, P 1-105 (John Wiley & Sons 1968), CONCISE ENCYCLOPEDIA OFPOLYMER SCIENCE AND Technology, p 748-761 (John Wiley & Sons, 1990), and10 ENCYCLOPEDIA OF POLYMER SCIENCE AND TECHNOLOGY, p 392-414 (John Wiley& Sons 1969). Commercially available thermoplastic polyamides may beadvantageously used in the practice of this invention, with linearcrystalline polyamides having a softening point or melting point between160° C. and 260° C. being preferred.

Suitable thermoplastic polyesters which may be employed include thepolymer reaction products of one or a mixture of aliphatic or aromaticpolycarboxylic acids esters of anhydrides and one or a mixture of diols.Examples of satisfactory polyesters include poly(trans-1,4-cyclohexylene C₂₋₆ alkane dicarboxylates such aspoly(trans-1,4-cyclohexylene succinate) and poly(trans-1,4-cyclohexylene adipate); poly (cis ortrans-1,4-cyclohexanedimethylene) alkanedicarboxylates such aspoly(cis-1,4-cyclohexanedimethylene) oxlate andpoly-(cis-1,4-cyclohexanedimethylene) succinate, poly (C₂₋₄ alkyleneterephthalates) such as polyethyleneterephthalate andpolytetramethylene-terephthalate, poly (C₂₋₄ alkylene isophthalates suchas polyethyleneisophthalate and polytetramethylene-isophthalate and likematerials. Preferred polyesters are derived from aromatic dicarboxylicacids such as naphthalenic or phthalic acids and C₂ to C₄ diols, such aspolyethylene terephthalate and polybutylene terephthalate. Preferredpolyesters will have a melting point in the range of 160° C. to 260° C.

Poly(phenylene ether) (PPE) thermoplastic resins which may be used inaccordance with this invention are well known, commercially availablematerials produced by the oxidative coupling polymerization of alkylsubstituted phenols. They are generally linear, amorphous polymershaving a glass transition temperature in the range of 190° C. to 235° C.These polymers, their method of preparation and compositions withpolystyrene are further described in U.S. Pat. No. 3,383,435.

Other thermoplastic resins which may be used include the polycarbonateanalogs of the polyesters described above such as segmented poly (etherco-phthalates); polycaprolactone polymers; styrene resins such ascopolymers of styrene with less than 50 mol % of acrylonitrile (SAN) andresinous copolymers of styrene, acrylonitrile and butadiene (ABS);sulfone polymers such as polyphenyl sulfone; copolymers and homopolymersof ethylene and C₂ to C₈ α-olefins, in one embodiment a homopolymer ofpropylene derived units, and in another embodiment a random copolymer orblock copolymer of ethylene derived units and propylene derived units,and like thermoplastic resins as are known in the art.

In another embodiment the compositions of this invention furthercomprising any of the thermoplastic resins (also referred to as athermoplastic or a thermoplastic polymer) described above are formedinto dynamically vulcanized alloys.

The term “dynamic vulcanization” is used herein to connote avulcanization process in which the engineering resin and a vulcanizableelastomer are vulcanized under conditions of high shear. As a result,the vulcanizable elastomer is simultaneously crosslinked and dispersedas fine particles of a “micro gel” within the engineering resin matrix.

Dynamic vulcanization is effected by mixing the ingredients at atemperature which is at or above the curing temperature of the elastomerin equipment such as roll mills, Banbury™, mixers, continuous mixers,kneaders or mixing extruders, e.g., twin screw extruders. The uniquecharacteristic of the dynamically cured compositions is that,notwithstanding the fact that the elastomer component may be fullycured, the compositions can be processed and reprocessed by conventionalrubber processing techniques such as extrusion, injection molding,compression molding, etc. Scrap or flashing can be salvaged andreprocessed.

Particularly preferred thermoplastic polymers useful in DVA's of thisinvention include engineering resins selected from the group consistingof polyamides, polycarbonates, polyesters, polysulfones, polylactones,polyacetals, acrylonitrile-butadiene-styrene resins (ABS),polyphenyleneoxide (PPO), polyphenylene sulfide (PPS),styrene-acrylonitrile resins (SAN), polyimides, styrene maleic anhydride(SMA), aromatic polyketones (PEEK, PEK, and PEKK) and mixtures thereof.Preferred engineering resins are polyamides. The more preferredpolyamides are nylon 6 and nylon 11. Preferably the engineering resin(s)may suitably be present in an amount ranging from about 10 to 98 wt %,preferably from about 20 to 95 wt %, the elastomer may be present in anamount ranging from about 2 to 90 wt %, preferably from about 5 to 80 wt%, based on the polymer blend. Preferably the elastomer is present insaid composition as particles dispersed in said engineering resin.

In a preferred embodiment the elastomer is selected frompoly(isobutylene-co-alkylstyrene), preferablypoly(isobutylene-co-p-methylstyrene), halogenatedpoly(isobutylene-co-alkylstyrene), preferably halogenatedpoly(isobutylene-co-p-methylstyrene), star branched butyl rubber,halogenated star-branched butyl rubber, butyl rubber, halogenated butylrubber, and mixtures thereof. In another preferred embodiment theelastomer comprises bromobutyl rubber and or chlorobutyl rubber.

The elastomer may be present in the elastomeric composition in a rangefrom up to 90 phr in one embodiment, from up to 50 phr in anotherembodiment, from up to 40 phr in another embodiment, and from up to 30phr in yet another embodiment. In yet another embodiment, the elastomermay be present from at least 2 phr, and from at least 5 phr in anotherembodiment, and from at least 5 phr in yet another embodiment, and fromat least 10 phr in yet another embodiment. A desirable embodiment mayinclude any combination of any upper phr limit and any lower phr limit.

In other embodiments, the elastomer, either individually or as a blend(i.e., reactor blends, physical blends such as by melt mixing) ofelastomers may be present in the composition from 5 to 90 phr in oneembodiment, and from 10 to 80 phr in another embodiment, and from 30 to70 phr in yet another embodiment, and from 40 to 60 phr in yet anotherembodiment, and from 5 to 50 phr in yet another embodiment, and from 5to 40 phr in yet another embodiment, and from 20 to 60 phr in yetanother embodiment, and from 20 to 50 phr in yet another embodiment, thechosen embodiment depending upon the desired end use application of thecomposition.

The elastomeric compositions may also contain at least one otherelastomer or two or more elastomers. The elastomer(s) may also becombined with other materials or polymers.

In certain embodiments and where applicable, the elastomers used in thepractice of the invention can be linear, substantially linear, blocky orbranched.

The elastomeric compositions may also include a variety of othercomponents as discussed in greater detail below and may be optionallycured to form cured elastomeric compositions that ultimately arefabricated into end use articles, as described in greater detail below.

Plastomers

The plastomers that are useful in the present invention can be describedas polyolefin copolymers having a density of from 0.85 to 0.915 g/cm³and a melt index (MI) between 0.10 and 30 dg/min. In one embodiment, theuseful plastomer is a copolymer of ethylene derived units and at leastone of C₃ to C₁₀ α-olefin derived units, the copolymer having a densityin the range of less than 0.915 g/cm³. The amount of comonomer (C₃ toC₁₀ α-olefin derived units) present in the plastomer ranges from 2 to 35wt % in one embodiment, and from 5 to 30 wt % in another embodiment, andfrom 15 to 25 wt % in yet another embodiment, and from 20 to 30 wt % inyet another embodiment.

The plastomer useful in the invention has a melt index (MI) of between0.1 and 20 dg/min (ASTM D1238; 190° C., 2.1 kg) in one embodiment, andfrom 0.2 to 10 dg/min in another embodiment, and from 0.3 to 8 dg/min inyet another embodiment. The average molecular weight of usefulplastomers ranges from 10,000 to 800,000 in one embodiment, and from20,000 to 700,000 in another embodiment. The 1% secant flexural modulus(ASTM D790) of useful plastomers ranges from 10 MPa to 150 MPa in oneembodiment, and from 20 MPa to 100 MPa in another embodiment. Further,the plastomer that is useful in compositions of the present inventionhas a melting temperature (Tm) of from 50° C. to 62° C. (first meltpeak) and from 65° C. to 85° C. (second melt peak) in one embodiment,and from 52° C. to 60° C. (first melt peak) and from 70° C. to 80° C.(second melt peak) in another embodiment.

Plastomers useful in the present invention are metallocene catalyzedcopolymers of ethylene derived units and higher α-olefin derived unitssuch as propylene, 1-butene, 1-hexene and 1-octene, and which containenough of one or more of these comonomer units to yield a densitybetween 0.860 and 0.900 g/cm³ in one embodiment. The molecular weightdistribution (Mw/Mn) of desirable plastomers ranges from 2 to 5 in oneembodiment, and from 2.2 to 4 in another embodiment. Examples of acommercially available plastomers are EXACT™ 4150, a copolymer ofethylene and 1-hexene, the 1-hexene derived units making up from 18 to22 wt % of the plastomer and having a density of 0.895 g/cm³ and MI of3.5 dg/min (ExxonMobil Chemical Company, Houston, Tex.); and EXACT™8201, a copolymer of ethylene and 1-octene, the 1-octene derived unitsmaking up from 26 to 30 wt % of the plastomer, and having a density of0.882 g/cm³ and MI of 1.0 dg/min (ExxonMobil Chemical Company, Houston,Tex.).

Processing Aids

Functionalized Polymer

The invention provides for a process to produce an elastomericcomposition, the process comprising contacting at least one elastomerwith a processing aid, wherein the processing aid comprises at least onefunctionalized polymer having at least one anhydride group.

The at least one functionalized polymer may be prepared byfunctionalizing at least one polymer with at least one anhydride. Forexample, a manufacturing process for making the at least onefunctionalized polymer involves solution functionalization of a polymerwith an anhydride via either thermal ENE reaction or in the presence ofchlorine.

In certain embodiments, the at least one polymer may be derived from apolymer polymerized from monomers including one or more of olefins,alpha-olefins, disubstituted olefins, isoolefins, conjugated dienes,non-conjugated dienes, styrenics and/or substituted styrenics and vinylethers. For example, the monomers may contain 2 to 20 carbon atoms,alternatively 2 to 12, and alternatively 4 to 10 carbon atoms.

In an embodiment, the functionalized polymer comprises C₂-C₁₂ α-olefinderived units.

In another embodiment, the functionalized polymer comprises C₄-C₁₀isoolefin derived units.

In yet another embodiment, the functionalized polymer comprisesisobutylene derived units.

The at least one anhydride group may be derived from the groupconsisting of maleic anhydride, itaconic a anhydride, citraconicanhydride, propenyl succinic anhydride, 2-pentenedioic anhydrides, andmixtures thereof. Illustrative examples may be represented by thegeneral formulas:

Such functionalized polymers are widely available and commonly used aslubricant additives. Examples of suppliers of such products includeInfineum International Ltd., Linden, N.J., and Chevron Oronite, Company,Houston, Tex.

In an embodiment, the at least one functionalized polymer is succinicanhydride functionalized polyisobutylene (PIBSA). For example, amanufacturing process for making PIBSA may involve solutionfunctionalization of a polyisobutylene or polybutene (PIB) such as a lowmolecular weight PIB with maleic anhydride via either thermal ENEreaction (thermal PIBSA) or in the presence of chlorine (chloro-PIBSA).As with all the polymers to be functionalized where applicable, thestarting PIB can be made from pure isobutylene monomer or a mixture ofbutene isomers.

In certain embodiments, the number average molecular weight (by gelpermeation chromatography) of the starting polymer such as PIB rangesfrom about 400 (the weight of the molecule in atomic mass units relativeto hydrogen atom assigned a value of 1.0) to about 5,000 or higher,alternatively, from about 500 to about 2,500, alternatively, from about800 to about 2,500, and alternatively, from about 800 to about 1,500.

In certain embodiments, the anhydride functionality of the at least onefunctionalized polymer such as PIBSA can range from about 0.5 mol % toabout 2.0 mol %, alternatively, from about 0.8 mol % to about 1.7 mol %,and alternatively, from about 1.0 mol % to about 1.5 mol %.

Commercial examples include PIBSA 48 functionalized polymer fromInfineum referenced above and derived from 2,200 Mn PIB with ananhydride functionality of about 1.2 mol % and PIBSA 55 functionalizedpolymer derived from 2,200 Mn PIB with an anhydride functionality ofabout 1.4 mol %. Other commercial examples include OLOA 15500 PIBSA fromChevron Oronite referenced above and derived from 1,000 Mn PIB and OLOA15667 PIBSA derived from 1,300 Mn PIB.

In yet other embodiments, the processing aid as described above may havea number average molecular weight (Mn) as determined by gel permeationchromatography of less than 10,000 in one embodiment, less than 8000 inanother embodiment, and less than 6000 in yet another embodiment. In oneembodiment, the processing aid have a number average molecular weight ofgreater than 400, and greater than 700 in another embodiment, andgreater than 900 in yet another embodiment. A preferred embodiment canbe a combination of any lower molecular weight limit with any uppermolecular weight limit herein. For example, in one embodiment, theprocessing aid may have a number average molecular weight of from 400 to10,000, and from 700 to 8000 in another embodiment, and from 900 to 3000in yet another embodiment.

In certain embodiments, the processing aid may have a number averagemolecular weight (Mn) of from 450 to 5,000; alternatively, from 500 to2,500; alternatively, from 900 to 2,500; alternatively, of about 1,000;alternatively, of about 1,300; and alternatively, of about 2,300.

Exemplary viscosities (ASTM D445) of the processing aid may range fromabout 10 to about 6000 cSt (centiStokes) at 100° C. in one embodiment,alternatively, from about 35 to about 1000 cSt at 100° C.,alternatively, from about 75 to about 500 cSt at 100° C., alternatively,from about 100 to about 300 cSt at 100° C., alternatively, from about100 to about 200 cSt at 100° C., and is greater than 35 cSt at 100° C.in yet another embodiment, and greater than 100 cSt at 100° C. in yetanother embodiment.

In yet other embodiments, the viscosities of the processing aid mayrange from 10 to 6000 cSt (centiStokes) at 100° C. in one embodiment,and from 35 to 5000 cSt at 100° C. in another embodiment. In otherembodiments, the viscosity is greater than 35 cSt at 100° C. in yetanother embodiment, and greater than 100 cSt at 100° C. in yet anotherembodiment.

The elastomeric composition comprises or is prepared with from 1 to 60phr in one embodiment, from 2 to 40 phr in another embodiment, from 3 to35 phr in another embodiment, from 4 to 30 phr in yet anotherembodiment, from 2 to 10 phr in yet another embodiment, from 3 to 25 phrin yet another embodiment, and from 2 to 20 phr in yet anotherembodiment of the processing aid as described above, wherein a desirablerange of processing aid may be any upper phr limit combined with anylower phr limit described herein.

In an embodiment, the processing aid or elastomeric composition does notcontain aromatic groups or unsaturation.

In another embodiment, the processing aid or elastomeric composition isfree or substantially free of or may have only contamination levels ofaromatic, napthenic, parafinnic oils, or mixtures thereof. As used here,“substantially free” refers to 1,000 ppm or less, alternatively, 800 ppmor less, alternatively, 500 ppm or less, alternatively, 250 ppm or less,alternatively, 100 ppm or less, alternatively, 75 ppm or less,alternatively, 50 ppm or less, alternatively, 20 ppm or less,alternatively, 15 ppm or less, alternatively, 10 ppm or less, and,alternatively, 5 ppm or less.

In yet other embodiments, the processing aid or elastomeric compositionmay include other components such as the following.

Polybutenes

In one aspect of the invention, a polybutene processing oil may bepresent in air barrier compositions. In one embodiment of the invention,the polybutene processing oil is a low molecular weight (less than15,000 Mn) homopolymer or copolymer of olefin derived units having from3 to 8 carbon atoms in one embodiment, preferably from 4 to 6 carbonatoms in another embodiment. In yet another embodiment, the polybuteneis a homopolymer or copolymer of a C₄ raffinate. An embodiment of suchlow molecular weight polymers termed “polybutene” polymers is describedin, for example, SYNTHETIC LUBRICANTS AND HIGH-PERFORMANCE FUNCTIONALFLUIDS p 357-392 (Rudnick & Shubkin, ed., Marcel Dekker 1999)(hereinafter “polybutene processing oil” or “polybutene”).

In one embodiment of the invention, the polybutene processing oil is acopolymer of at least isobutylene derived units, 1-butene derived units,and 2-butene derived units. In one embodiment, the polybutene is ahomopolymer, copolymer, or terpolymer of the three units, wherein theisobutylene derived units are from 40 to 100 wt % of the copolymer, the1-butene derived units are from 0 to 40 wt % of the copolymer, and the2-butene derived units are from 0 to 40 wt % of the copolymer. Inanother embodiment, the polybutene is a copolymer or terpolymer of thethree units, wherein the isobutylene derived units are from 40 to 99 wt% of the copolymer, the 1-butene derived units are from 2 to 40 wt % ofthe copolymer, and the 2-butene derived units are from 0 to 30 wt % ofthe copolymer. In yet another embodiment, the polybutene is a terpolymerof the three units, wherein the isobutylene derived units are from 40 to96 wt % of the copolymer, the 1-butene derived units are from 2 to 40 wt% of the copolymer, and the 2-butene derived units are from 2 to 20 wt %of the copolymer. In yet another embodiment, the polybutene is ahomopolymer or copolymer of isobutylene and 1-butene, wherein theisobutylene derived units are from 65 to 100 wt % of the homopolymer orcopolymer, and the 1-butene derived units are from 0 to 35 wt % of thecopolymer.

Polybutene processing oils useful in the invention typically have anumber average molecular weight (Mn) of less than 10,000 in oneembodiment, less than 8000 in another embodiment, and less than 6000 inyet another embodiment. In one embodiment, the polybutene oil has anumber average molecular weight of greater than 400, and greater than700 in another embodiment, and greater than 900 in yet anotherembodiment. A preferred embodiment can be a combination of any lowermolecular weight limit with any upper molecular weight limit herein. Forexample, in one embodiment of the polybutene of the invention, thepolybutene has a number average molecular weight of from 400 to 10,000,and from 700 to 8000 in another embodiment, and from 900 to 3000 in yetanother embodiment. Useful viscosities of the polybutene processing oilranges from 10 to 6000 cSt (centiStokes) at 100° C. in one embodiment,and from 35 to 5000 cSt at 100° C. in another embodiment, and is greaterthan 35 cSt at 100° C. in yet another embodiment, and greater than 100cSt at 100° C. in yet another embodiment.

Commercial examples of such a processing oil are the PARAPOL™ Series ofprocessing oils (ExxonMobil Chemical Company, Houston, Tex.), such asPARAPOL™ 450, 700, 950, 1300, 2400 and 2500; ORONITE™ (ChevronTexaco,New Orleans, La.); DAELIM POLYBUTENE™ (Daelim Industrial Co., Ltd.,Korea); INDOPOL™ (Innovene USA LLC, Lisle, Ill.); TPC PIB (TexasPetrochemicals, Houston, Tex.). The commercially available PARAPOL™Series of polybutene processing oils are synthetic liquid polybutenes,each individual formulation having a certain molecular weight, allformulations of which can be used in the composition of the invention.The molecular weights of the PARAPOL™ oils are from 420 Mn (PARAPOL™450) to 2700 Mn (PARAPOL™ 2500) as determined by gel permeationchromatography. The MWD of the PARAPOL™ oils range from 1.8 to 3 in oneembodiment, and from 2 to 2.8 in another embodiment.

The table below shows some of the properties of the PARAPOL™ oils usefulin embodiments of the present invention, wherein the viscosity wasdetermined as per ASTM D445, and the molecular weight by gel permeationchromatography.

Properties of individual PARAPOL ™ Processing Aids Grade Mn Viscosity @100° C., cSt 450 420 10.6 700 700 78 950 950 230 1300 1300 630 2400 23503200 2500 2700 4400

Other properties of PARAPOL™ processing oils are as follows: the density(g/mL) of PARAPOL™ processing oils varies from about 0.85 (PARAPOL™ 450)to 0.91 (PARAPOL™ 2500). The bromine number (CG/G) for PARAPOL™ oilsranges from 40 for the 450 Mn processing oil, to 8 for the 2700 Mnprocessing oil.

The elastomeric composition of the invention may include one or moretypes of polybutene as a mixture, blended either prior to addition tothe elastomer, or with the elastomer. The amount and identity (e.g.,viscosity, Mn, etc.) of the polybutene processing oil mixture can bevaried in this manner. Thus, PARAPOL™ 450 can be used when low viscosityis desired in the composition of the invention, while PARAPOL™ 2500 canbe used when a higher viscosity is desired, or compositions thereof toachieve some other viscosity or molecular weight. In this manner, thephysical properties of the composition can be controlled. Moreparticularly, the phrases “polybutene processing oil”, or “polybuteneprocessing oil” include a single oil or a composition of two or moreoils used to obtain any viscosity or molecular weight (or otherproperty) desired, as specified in the ranges disclosed herein.

The polybutene processing oil or oils are present in the elastomericcomposition of the invention from 1 to 60 phr in one embodiment, andfrom 2 to 40 phr in another embodiment, from 4 to 35 phr in anotherembodiment, and from 5 to 30 phr in yet another embodiment, and from 2to 10 phr in yet another embodiment, and from 5 to 25 phr in yet anotherembodiment, and from 2 to 20 phr in yet another embodiment, wherein adesirable range of polybutene may be any upper phr limit combined withany lower phr limit described herein. Preferably, the polybuteneprocessing oil does not contain aromatic groups or unsaturation.

The polyolefin compositions of the present invention include anon-functionalized plastizer (“NFP”). The NFP of the present inventionis a compound comprising carbon and hydrogen, and does not include to anappreciable extent functional groups selected from hydroxide, aryls andsubstituted aryls, halogens, alkoxys, carboxylates, esters, carbonunsaturation, acrylates, oxygen, nitrogen, and carboxyl. By “appreciableextent”, it is meant that these groups and compounds comprising thesegroups are not deliberately added to the NFP, and if present at all, arepresent to less than 5 wt % by weight of the NFP in one embodiment, andless than 1 wt % in another embodiment, and less than 0.5 wt % in yetanother embodiment.

In one embodiment, the NFP consists of C₆ to C₂₀₀ paraffins, and C₈ toC₁₀₀ paraffins in another embodiment. In another embodiment, the NFPconsists essentially of C₆ to C₂₀₀ paraffins, and consists essentiallyof C₈ to C₁₀₀ paraffins in another embodiment. For purposes of thepresent invention and description herein, the term “paraffin” includesall isomers such as n-paraffins, branched paraffins, isoparaffins, andmay include cyclic aliphatic species, and blends thereof, and may bederived synthetically by means known in the art, or from refined crudeoil in such a way as to meet the requirements described for desirableNFPs described herein. It will be realized that the classes of materialsdescribed herein that are useful as a NFPs can be utilized alone oradmixed with other NFPs described herein in order to obtain the desiredproperties.

The NFP may be present in the polyolefin compositions of the inventionfrom 0.1 to 60 wt % in one embodiment, and from 0.5 to 40 wt % inanother embodiment, and from 1 to 20 wt % in yet another embodiment, andfrom 2 to 10 wt % in yet another embodiment, wherein a desirable rangemay comprise any upper wt % limit with any lower wt % limit describedherein.

The NFP may also be described by any number of, or any combination of,parameters described herein. In one embodiment, the NFP of the presentinvention has a pour point of from less than 0° C. in one embodiment,and less than −5° C. in another embodiment, and less than −10° C. inanother embodiment, less than −20° C. in yet another embodiment, lessthan −40° C. in yet another embodiment, less than −50° C. in yet anotherembodiment, and less than −60° C. in yet another embodiment, and greaterthan −120° C. in yet another embodiment, and greater than −200° C. inyet another embodiment, wherein a desirable range may include any upperpour point limit with any lower pour point limit described herein. Inone embodiment, the NFP is a paraffin or other compound having a pourpoint of less than −30° C., and between −30° C. and −90° C. in anotherembodiment, in the viscosity range of from 0.5 to 200 cSt at 40° C.(ASTM D445). Most mineral oils, which typically include aromaticmoieties and other functional groups, have a pour point of from 10° C.to −20° C. at the same viscosity range.

The NFP may have a dielectric constant at 20° C. of less than 3.0 in oneembodiment, and less than 2.8 in another embodiment, less than 2.5 inanother embodiment, and less than 2.3 in yet another embodiment, andless than 2.1 in yet another embodiment. Polyethylene and polypropyleneeach have a dielectric constant (1 kHz, 23° C.) of at least 2.3 (CRCHANDBOOK OF CHEMISTRY AND PHYSICS (Lide, ed. 82^(d) ed. CRC Press 2001).

The NFP has a viscosity (ASTM D445) of from 0.1 to 3000 cSt at 100° C.,and from 0.5 to 1000 cSt at 100° C. in another embodiment, and from 1 to250 cSt at 100° C. in another embodiment, and from 1 to 200 cSt at 100°C. in yet another embodiment, and from 10 to 500 cSt at 100° C. in yetanother embodiment, wherein a desirable range may comprise any upperviscosity limit with any lower viscosity limit described herein.

The NFP has a specific gravity (ASTM D4052, 15.6/15.6° C.) of less than0.920 g/cm³ in one embodiment, and less than 0.910 g/cm³ in anotherembodiment, and from 0.650 to 0.900 g/cm³ in another embodiment, andfrom 0.700 to 0.860 g/cm³, and from 0.750 to 0.855 g/cm³ in anotherembodiment, and from 0.790 to 0.850 g/cm³ in another embodiment, andfrom 0.800 to 0.840 g/cm³ in yet another embodiment, wherein a desirablerange may comprise any upper specific gravity limit with any lowerspecific gravity limit described herein. The NFP has a boiling point offrom 100° C. to 800° C. in one embodiment, and from 200° C. to 600° C.in another embodiment, and from 250° C. to 500° C. in yet anotherembodiment. Further, the NFP has a weight average molecular weight (GPCor GC) of less than 20,000 g/mol in one embodiment, and less than 10,000g/mol in yet another embodiment, and less than 5,000 g/mol in yetanother embodiment, and less than 4,000 g/mol in yet another embodiment,and less than 2,000 g/mol in yet another embodiment, and less than 500g/mol in yet another embodiment, and greater than 100 g/mol in yetanother embodiment, wherein a desirable molecular weight range can beany combination of any upper molecular weight limit with any lowermolecular weight limit described herein.

A compound suitable as an NFP for polyolefins of the present inventionmay be selected from commercially available compounds such as so called“isoparaffins”, “polyalphaolefins” (PAOs) and “polybutenes” (a subgroupof PAOs). These three classes of compounds can be described as paraffinswhich can include branched, cyclic, and normal structures, and blendsthereof. These NFPs can be described as comprising C₆ to C₂₀₀ paraffinsin one embodiment, and C₈ to C₁₀₀ paraffins in another embodiment.

Isoparaffins

The so called “isoparaffins” are described as follows. These paraffinsare desirably isoparaffins, meaning that the paraffin chains possess C₁to C₁₀ alkyl branching along at least a portion of each paraffin chain.The C₆ to C₂₀₀ paraffins may comprise C₆ to C₂₅ isoparaffins in oneembodiment, and C₈ to C₂₀ isoparaffins in another embodiment.

More particularly, the isoparaffins are saturated aliphatic hydrocarbonswhose molecules have at least one carbon atom bonded to at least threeother carbon atoms or at least one side chain (i.e., a molecule havingone or more tertiary or quaternary carbon atoms), and preferably whereinthe total number of carbon atoms per molecule is in the range between 6to 50, and between 10 and 24 in another embodiment, and from 10 to 15 inyet another embodiment. Various isomers of each carbon number willtypically be present. The isoparaffins may also include cycloparaffinswith branched side chains, generally as a minor component of theisoparaffin. The density (ASTM D4052, 15.6/15.6° C.) of theseisoparaffins ranges from 0.70 to 0.83 g/cm³; a pour point of below −40°C. in one embodiment, and below −50° C. in another embodiment; aviscosity (ASTM 445, 25° C.) of from 0.5 to 20 cSt at 25° C.; andaverage molecular weights in the range of 100 to 300 g/mol. Theisoparaffins are commercially available under the trade name ISOPAR(ExxonMobil Chemical Company, Houston Tex.), and are described in, forexample, U.S. Pat. No. 6,197,285, U.S. Pat. No. 3,818,105 and U.S. Pat.No. 3,439,088, and sold commercially as ISOPAR™ series of isoparaffins.

ISOPAR Series Isoparaffins Pour Viscosity @ Distillation Point Avg.Specific 25° C. Saturates and Name Range (° C.) (° C.) Gravity (g/cm³)(cSt) Aromatics (wt %) ISOPAR E 117-136 −63 0.72 0.85 <0.01 ISOPAR G161-176 −57 0.75 1.46 <0.01 ISOPAR H 178-188 −63 0.76 1.8 <0.01 ISOPAR K179-196 −60 0.76 1.85 <0.01 ISOPAR L 188-207 −57 0.77 1.99 <0.01 ISOPARM 223-254 −57 0.79 3.8 <0.01 ISOPAR V 272-311 −63 0.82 14.8 <0.01

In another embodiment, the isoparaffins are a mixture of branched andnormal paraffins having from 6 to 50 carbon atoms, and from 10 to 24carbon atoms in another embodiment, in the molecule. The isoparaffincomposition has an a branch paraffin:n-paraffin ratio ranging from 0.5:1to 9:1 in one embodiment, and from 1:1 to 4:1 in another embodiment. Theisoparaffins of the mixture in this embodiment contain greater than 50wt % (by total weight of the isoparaffin composition) mono-methylspecies, for example, 2-methyl, 3-methyl, 4-methyl, 5-methyl or thelike, with minimum formation of branches with substituent groups ofcarbon number greater than 1, such as, for example, ethyl, propyl, butylor the like, based on the total weight of isoparaffins in the mixture.In one embodiment, the isoparaffins of the mixture contain greater than70 wt % of the mono-methyl species, based on the total weight of theisoparaffins in the mixture. The isoparaffinic mixture boils within arange of from 100° C. to 350° C. in one embodiment, and within a rangeof from 110° C. to 320° C. in another embodiment. In preparing thedifferent grades, the paraffinic mixture is generally fractionated intocuts having narrow boiling ranges, for example, 35° C. boiling ranges.These branch paraffin/n-paraffin blends are described in, for example,U.S. Pat. No. 5,906,727.

Other suitable isoparaffins are also commercial available under thetrade names SHELLSOL™ (Royal Dutch/Shell Group of Companies), SOLTROL™(Chevron Phillips Chemical Co. LP) and SASOL™ (by Sasol Limited,Johannesburg, South Africa). Commercial examples are SHELLSOL™ (boilingpoint=215-260° C.), SOLTROL 220 (boiling point=233-280° C.), and SASOLLPA-210 and SASOL-47 (boiling point=238-274° C.).

Polyalphaolefins

The paraffins suitable as the NFP of the invention also include socalled polyalphaolefins (PAOs), which are described as follows. The PAOsuseful in the present invention comprise C₆ to C₂₀₀ paraffins, and C₁₀to C₁₀₀ n-paraffins in another embodiment. The PAOs are dimers, trimers,tetramers, pentamers, etc. of C₄ to C₁₂ α-olefins in one embodiment, andC₅ to C₁₂ α-olefins in another embodiment. Suitable olefins include1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene,1-undodecene and 1-dodecene. In one embodiment, the olefin is 1-decene,and the NFP is a mixture of dimers, trimers, tetramers and pentamers(and higher) of 1-decene. The PAOs are described more particularly in,for example, U.S. Pat. No. 5,171,908, and U.S. Pat. No. 5,783,531 and inSYNTHETIC LUBRICANTS AND HIGH-PERFORMANCE FUNCTIONAL FLUIDS, P 1-52(Rudnick & Shubkin, ed. Marcel Dekker, Inc. 1999).

The PAOs of the present invention possess a weight average molecularweight of from 100 to 20,000 in one embodiment, and from 200 to 10,000in another embodiment, and from 200 to 7,000 in yet another embodiment,and from 200 to 2,000 in yet another embodiment, and from 200 to 500 inyet another embodiment. Generally, PAOs have viscosities in the range of0.1 to 150 cSt at 100° C., and from 0.1 to 3000 cSt at 100° C. inanother embodiment (ASTM D445). The PAOs useful in the present inventionhave pour points of less than 0° C. in one embodiment, less than −10° C.in another embodiment, and less than −20° C. in yet another embodiment,and less than −40° C. in yet another embodiment. Desirable PAOs arecommercially available as SHF and SuperSyn PAOs (ExxonMobil ChemicalCompany, Houston, Tex.).

SHF and SuperSyn Series Polyalphaolefins Specific Gravity (g/cm³;Viscosity @ Pour Point, PAO 15.6/15.6° C.) 100° C., cSt VI ° C. SHF-200.798 1.68 — −63 SHF-21 0.800 1.70 — −57 SHF-23 0.802 1.80 — −54 SHF-410.818 4.00 123 −57 SHF-61/63 0.826 5.80 133 −57 SHF-82/83 0.833 7.90 135−54 SHF-101 0.835 10.0 136 −54 SHF-403 0.850 40.0 152 −39 SHF-1003 0.855107 179 −33 SuperSyn 2150 0.850 150 214 −42 SuperSyn 2300 0.852 300 235−30 SuperSyn 21000 0.856 1,000 305 −18 SuperSyn 23000 0.857 3,000 388 −9

Other processing aids include esters, polyethers, and polyalkyleneglycols.

Other processing aids may be present or used in the manufacture of theelastomeric compositions of the invention. Processing aids include, butare not limited to, plasticizers, tackifiers, extenders, chemicalconditioners, homogenizing agents and peptizers such as mercaptans,petroleum and vulcanized vegetable oils, mineral oils, paraffinic oils,polybutene aids, naphthenic oils, aromatic oils, waxes, resins, rosins,and the like.

Certain mineral oils, distinguished by their viscosity indices and theamount of saturates and sulfur they contain, have been classified asHydrocarbon Basestock Group I, II or III by the American PetroleumInstitute (API). Group I basestocks are solvent refined mineral oils.They contain the most unsaturates and sulfur and have the lowestviscosity indices.

Groups II and III are the High Viscosity Index and Very High ViscosityIndex mineral oils. They are hydroprocessed mineral oils. The Group IIIoils contain less unsaturates and sulfur than the Group I oils and havehigher viscosity indices than the Group II oils do. Rudnick and Shubkinin Synthetic Lubricants and High-Performance Functional Fluids, Secondedition, Rudnick, Shubkin, eds., Marcel Dekker, Inc. New York, 1999,describe the mineral oils as typically being:

Group I—mineral oils refined using solvent extraction of aromatics,solvent dewaxing, hydrofining to reduce sulfur content to producemineral oils with sulfur levels greater than 0.03 wt %, saturates levelsof 60 to 80% and a viscosity index of about 90;

Group II—mildly hydrocracked mineral oils with conventional solventextraction of aromatics, solvent dewaxing, and more severe hydrofiningto reduce sulfur levels to less than or equal to 0.03 wt % as well asremoving double bonds from some of the olefinic and aromatic compounds,saturate levels are greater than 95-98% and VI is about 80-120; and

Group III—severely hydrotreated mineral oils with saturates levels ofsome oils virtually 100%, sulfur contents are less than or equal to 0.03wt % (preferably between 0.001 and 0.01%) and VI is in excess of 120.

The processing aid is typically present or used in the manufacturingprocess from 1 to 70 phr in one embodiment, from 3 to 60 phr in anotherembodiment, and from 5 to 50 phr in yet another embodiment.

In one embodiment of the invention, paraffinic, naphthenic and/oraromatic oils are substantially absent, meaning, they have not beendeliberately added to the compositions, or, in the alternative, ifpresent, are only present up to 0.2 wt % of the compositions used tomake the air barriers.

Fillers

The elastomeric composition may have one or more filler components suchas, for example, calcium carbonate, silica, clay and other silicateswhich may or may not be exfoliated, mica, talc, titanium dioxide, andcarbon black.

The fillers of the present invention may be any size and typicallyrange, for example, from about 0.0001 μm to about 100 μm. As usedherein, silica is meant to refer to any type or particle size silica oranother silicic acid derivative, or silicic acid, processed by solution,pyrogenic or the like methods and having a surface area, includinguntreated, precipitated silica, crystalline silica, colloidal silica,aluminum or calcium silicates, fumed silica, and the like.

In one embodiment, the filler is carbon black or modified carbon black,and combinations of any of these. In another embodiment, the filler is ablend of carbon black and silica. The preferred filler for such articlesas tire treads and sidewalls is reinforcing grade carbon black presentat a level of from 10 to 100 phr of the blend, more preferably from 30to 80 phr in another embodiment, and from 50 to 80 phr in yet anotherembodiment. Useful grades of carbon black, as described in RUBBERTECHNOLOGY, p 59-85, range from N110 to N990. More desirably,embodiments of the carbon black useful in, for example, tire treads areN229, N351, N339, N220, N234 and N110 provided in ASTM (D3037, D1510,and D3765). Embodiments of the carbon black useful in, for example,sidewalls in tires, are N330, N351, N550, N650, N660, and N762. Carbonblacks suitable for innerliners and other air barriers include N550,N660, N650, N762, N990 and Regal 85.

The layered filler may comprise a layered clay, optionally, treated orpre-treated with a modifying agent such as organic molecules. Theelastomeric compositions may incorporate a clay, optionally, treated orpre-treated with a modifying agent, to form a nanocomposite ornanocomposite composition.

Nanocomposites may include at least one elastomer as described above andat least one modified layered filler. The modified layered filler may beproduced by the process comprising contacting at least one layeredfiller such as at least one layered clay with at least one modifyingagent.

The modified layered filler may be produced by methods and usingequipment well within the skill in the art. For example, see U.S. Pat.No. 4,569,923, U.S. Pat. No. 5,663,111, U.S. Pat. No. 6,036,765, andU.S. Pat. No. 6,787,592. Illustrations of such methods are demonstratedin the Example section. However, by no means is this meant to be anexhaustive listing.

In an embodiment, the layered filler such as a layered clay may compriseat least one silicate.

In certain embodiments, the silicate may comprise at least one“smectite” or “smectite-type clay” referring to the general class ofclay minerals with expanding crystal lattices. For example, this mayinclude the dioctahedral smectites which consist of montmorillonite,beidellite, and nontronite, and the trioctahedral smectites, whichincludes saponite, hectorite, and sauconite. Also encompassed aresmectite-clays prepared synthetically, e.g., by hydrothermal processesas disclosed in U.S. Pat. No. 3,252,757, U.S. Pat. No. 3,586,468, U.S.Pat. No. 3,666,407, U.S. Pat. No. 3,671,190, U.S. Pat. No. 3,844,978,U.S. Pat. No. 3,844,979, U.S. Pat. No. 3,852,405, and U.S. Pat. No.3,855,147.

In yet other embodiments, the at least one silicate may comprise naturalor synthetic phyllosilicates, such as montmorillonite, nontronite,beidellite, bentonite, volkonskoite, laponite, hectorite, saponite,sauconite, magadite, kenyaite, stevensite and the like, as well asvermiculite, halloysite, aluminate oxides, hydrotalcite, and the like.Combinations of any of the previous embodiments are also contemplated.

The layered filler such as the layered clays described above may bemodified such as intercalated or exfoliated by treatment with at leastone modifying agent or swelling agent or exfoliating agent or additivecapable of undergoing ion exchange reactions with the cations present atthe interlayer surfaces of the layered filler.

Modifying agents are also known as swelling or exfoliating agents.Generally, they are additives capable of undergoing ion exchangereactions with the cations present at the interlayer surfaces of thelayered filler. Suitable exfoliating additives include cationicsurfactants such as ammonium, alkylamines or alkylammonium (primary,secondary, tertiary and quaternary), phosphonium or sulfoniumderivatives of aliphatic, aromatic or arylaliphatic amines, phosphinesand sulfides.

For example, amine compounds (or the corresponding ammonium ion) arethose with the structure R²R³R⁴N, wherein R², R³, and R⁴ are C₁ to C₃₀alkyls or alkenes in one embodiment, C₁ to C₂₀ alkyls or alkenes inanother embodiment, which may be the same or different. In oneembodiment, the exfoliating agent is a so-called long chain tertiaryamine, wherein at least R² is a C₁₄ to C₂₀ alkyl or alkene.

In other embodiments, a class of exfoliating additives include thosewhich can be covalently bonded to the interlayer surfaces. These includepolysilanes of the structure —Si(R⁵)₂R⁶ where R⁵ is the same ordifferent at each occurrence and is selected from alkyl, alkoxy oroxysilane and R⁶ is an organic radical compatible with the matrixpolymer of the composite.

Other suitable exfoliating additives include protonated amino acids andsalts thereof containing 2-30 carbon atoms such as 12-aminododecanoicacid, epsilon-caprolactam and like materials. Suitable swelling agentsand processes for intercalating layered silicates are disclosed in U.S.Pat. No. 4,472,538, U.S. Pat. No. 4,810,734, and U.S. Pat. No. 4,889,885as well as WO 92/02582.

In an embodiment, the exfoliating additive or additives are capable ofreacting with the halogen sites of the halogenated elastomer to formcomplexes which help exfoliate the clay. In certain embodiments, theadditives include all primary, secondary and tertiary amines andphosphines; alkyl and aryl sulfides and thiols; and their polyfunctionalversions. Desirable additives include: long-chain tertiary amines suchas N,N-dimethyl-octadecylamine, N,N-dioctadecyl-methylamine, so calleddihydrogenated tallowalkyl-methylamine and the like, andamine-terminated polytetrahydrofuran; long-chain thiol and thiosulfatecompounds like hexamethylene sodium thiosulfate.

In yet other embodiments, modifying agents include at least one polymerchain comprising a carbon chain length of from C₂₅ to C₅₀₀, wherein thepolymer chain also comprises an ammonium-functionalized group describedby the following group pendant to the polymer chain E:

wherein each R, R¹ and R² are the same or different and independentlyselected from hydrogen, C₁ to C₂₆ alkyl, alkenes or aryls, substitutedC₁ to C₂₋₆ alkyls, alkenes or aryls, C₁ to C₂₆ aliphatic alcohols orethers, C₁ to C₂₆ carboxylic acids, nitriles, ethoxylated amines,acrylates and esters; and wherein X is a counterion of ammonium such asBr⁻, Cl⁻ or PF₆ ⁻.

The modifying agent such as described herein is present in thecomposition in an amount to achieve optimal air retention as measured bythe permeability testing described herein. For example, but not limitedto, the additive may be employed from 0.1 to 40 phr in one embodiment,and from 0.2 to 20 phr in another embodiment, and from 0.3 to 10 phr inyet another embodiment.

The exfoliating additive may be added to the composition at any stage;for example, the additive may be added to the elastomer, followed byaddition of the layered filler, or may be added to a combination of atleast one elastomer and at least one layered filler; or the additive maybe first blended with the layered filler, followed by addition of theelastomer in yet another embodiment.

Examples of some commercial products are Cloisites produced by SouthernClay Products, Inc. in Gunsalas, Tex. For example, Cloisite Na⁺,Cloisite 30B, Cloisite 10A, Cloisite 25A, Cloisite 93A, Cloisite 20A,Cloisite 15A, and Cloisite 6A. They are also available as SOMASIF andLUCENTITE clays produced by CO-OP Chemical Co., LTD. In Tokyo, Japan.For example, SOMASIF™ MAE, SOMASIF™ MEE, SOMASIF™ MPE, SOMASIF™ MTE,SOMASIF™ ME-100, LUCENTITE™ SPN, and LUCENTITE(SWN).

The amount of clay or exfoliated clay incorporated in the nanocompositesin accordance with an embodiment of the invention is sufficient todevelop an improvement in the mechanical properties or barrierproperties of the nanocomposite, for example, tensile strength or oxygenpermeability. Amounts generally will range from 0.5 to 10 wt % in oneembodiment, and from 1 to 5 wt % in another embodiment, based on thepolymer content of the nanocomposite. Expressed in parts per hundredrubber, the clay or exfoliated clay may be present from 1 to 30 phr inone embodiment, and from 5 to 20 phr in another embodiment.

Crosslinking Agents, Curatives, Cure Packages, and Curing Processes

In certain embodiments, the elastomeric compositions and the articlesmade from those compositions may comprise or be manufactured with theaid of at least one cure package, at least one curative, at least onecrosslinking agent, and/or undergo a process to cure the elastomericcomposition. As used herein, at least one curative package refers to anymaterial or method capable of imparting cured properties to a rubber ascommonly understood in the industry. At least one curative package mayinclude any and at least one of the following.

One or more crosslinking agents are preferably used in the elastomericcompositions of the present invention, especially when silica is theprimary filler, or is present in combination with another filler.Crosslinking and curing agents include sulfur, zinc oxide, and fattyacids. More preferably, the coupling agent may be a bifunctionalorganosilane crosslinking agent. An “organosilane crosslinking agent” isany silane coupled filler and/or crosslinking activator and/or silanereinforcing agent known to those skilled in the art including, but notlimited to, vinyl triethoxysilane,vinyl-tris-(beta-methoxyethoxy)silane,methacryloylpropyltrimethoxysilane, gamma-amino-propyl triethoxysilane(sold commercially as A1100 by Witco),gamma-mercaptopropyltrimethoxysilane (A189 by Witco) and the like, andmixtures thereof. In one embodiment,bis-(3-triethoxysilypropyl)tetrasulfide (sold commercially as Si69 byDegussa) is employed.

Peroxide cure systems or resin cure systems may also be used.

Heat or radiation-induced crosslinking of polymers may be used.

Generally, polymer blends, for example, those used to produce tires, arecrosslinked thereby improve the polymer's mechanical properties. It isknown that the physical properties, performance characteristics, anddurability of vulcanized rubber compounds are directly related to thenumber (crosslink density) and type of crosslinks formed during thevulcanization reaction. (See, e.g., Helt et al., The Post VulcanizationStabilization for NR in RUBBER WORLD, p 18-23 (1991)).

Sulfur is the most common chemical vulcanizing agent fordiene-containing elastomers. It exists as a rhombic 8-member ring or inamorphous polymeric forms. The sulfur vulcanization system also consistsof the accelerator to activate the sulfur, an activator, and a retarderto help control the rate of vulcanization. Accelerators serve to controlthe onset of and rate of vulcanization, and the number and type ofsulfur crosslinks that are formed. These factors play a significant rolein determining the performance properties of the vulcanizate.

Activators are chemicals that increase the rate of vulcanization byreacting first with the accelerators to form rubber-soluble complexeswhich then react with the sulfur to form sulfurating agents. Generalclasses of accelerators include amines, diamines, guanidines, thioureas,thiazoles, thiurams, sulfenamides, sulfenimides, thiocarbamates,xanthates, and the like.

Retarders may be used to delay the initial onset of cure in order toallow sufficient time to process the unvulcanized rubber.

Halogen-containing elastomers such as halogenated star-branched butylrubber, brominated butyl rubber, chlorinated butyl rubber, star-branchedbrominated butyl (polyisobutylene/isoprene copolymer) rubber,halogenated poly(isobutylene-co-p-methylstyrene), polychloroprene, andchlorosulfonated polyethylene may be crosslinked by their reaction withmetal oxides. The metal oxide is thought to react with halogen groups inthe polymer to produce an active intermediate which then reacts furtherto produce carbon-carbon bonds. Zinc halide is liberated as a by-productand it serves as an autocatalyst for this reaction.

Generally, polymer blends may be crosslinked by adding curativemolecules, for example sulfur, metal oxides, organometallic compounds,radical initiators, etc., followed by heating. In particular, thefollowing metal oxides are common curatives that will function in thepresent invention: ZnO, CaO, MgO, Al₂O₃, CrO₃, FeO, Fe₂O₃, and NiO.These metal oxides can be used alone or in conjunction with thecorresponding metal fatty acid complex (e.g., zinc stearate, calciumstearate, etc.), or with the organic and fatty acids added alone, suchas stearic acid, and optionally other curatives such as sulfur or asulfur compound, an alkylperoxide compound, diamines or derivativesthereof (e.g., DIAK products sold by DuPont). (See also, FormulationDesign and Curing Characteristics of NBR Mixes for Seals, RUBBER WORLD,p 25-30 (1993)). This method of curing elastomers may be accelerated andis often used for the vulcanization of elastomer blends.

The acceleration of the cure process is accomplished in the presentinvention by adding to the composition an amount of an accelerant, oftenan organic compound. The mechanism for accelerated vulcanization ofnatural rubber involves complex interactions between the curative,accelerator, activators and polymers. Ideally, all of the availablecurative is consumed in the formation of effective crosslinks which jointogether two polymer chains and enhance the overall strength of thepolymer matrix. Numerous accelerators are known in the art and include,but are not limited to, the following: stearic acid, diphenyl guanidine(DPG), tetramethylthiuram disulfide (TMTD), 4,4′-dithiodimorpholine(DTDM), tetrabutylthiuram disulfide (TBTD), benzothiazyl disulfide(MBTS), hexamethylene-1,6-bisthiosulfate disodium salt dihydrate (soldcommercially as DURALINK™ HTS by Flexsys), 2-morpholinothiobenzothiazole (MBS or MOR), blends of 90% MOR and 10% MBTS (MOR 90),N-tertiarybutyl-2-benzothiazole sulfenamide (TBBS), and N-oxydiethylenethiocarbamyl-N-oxydiethylene sulfonamide (OTOS), zinc 2-ethyl hexanoate(ZEH), and “thioureas”.

Other Components

The compositions produced in accordance with the present inventiontypically contain other components and additives customarily used inrubber mixes, such as effective amounts of other nondiscolored andnondiscoloring processing aids, pigments, antioxidants, and/orantiozonants.

Processing

Blends of elastomers may be reactor blends and/or melt mixes. Mixing ofthe components may be carried out by combining the polymer components,filler and the clay in the form of an intercalate in any suitable mixingdevice such as a two-roll open mill, Brabender™ internal mixer, Banbury™internal mixer with tangential rotors, Krupp internal mixer withintermeshing rotors, or preferably a mixer/extruder, by techniques knownin the art. Mixing is performed at temperatures in the range from up tothe melting point of the elastomer and/or secondary rubber used in thecomposition in one embodiment, from 40° C. up to 250° C. in anotherembodiment, and from 100° C. to 200° C. in yet another embodiment, underconditions of shear sufficient to allow the clay intercalate toexfoliate and become uniformly dispersed within the polymer to form thenanocomposite.

Typically, from 70% to 100% of the elastomer or elastomers is firstmixed for 20 to 90 seconds, or until the temperature reaches from 40° C.to 75° C. Then, ¾ of the filler, and the remaining amount of elastomer,if any, are typically added to the mixer, and mixing continues until thetemperature reaches from 90° C. to 150° C. Next, the remaining filler isadded, as well as the processing aid, and mixing continues until thetemperature reaches from 140° C. to 190° C. The masterbatch mixture isthen finished by sheeting on an open mill and allowed to cool, forexample, to from 60° C. to 100° C. when the curatives are added.

Mixing with the clays is performed by techniques known to those skilledin the art, wherein the clay is added to the polymer at the same time asthe carbon black in one embodiment. The processing aid is typicallyadded later in the mixing cycle after the carbon black and clay haveachieved adequate dispersion in the elastomeric matrix.

The cured compositions of the invention can include various elastomersand fillers with the processing aid. The compositions of the inventiontypically include isobutylene-based elastomers such as halogenatedpoly(isobutylene-co-p-methylstyrene), butyl rubber, or halogenatedstar-branched butyl rubber (HSBB) either alone, or some combination withone another, with the processing aid being present from 3 to 30 phr inone embodiment.

In one embodiment, the composition is halogenated butyl rubber componentfrom 70 to 97 phr that may include a general purpose rubber from 3 to 30phr, and processing aid present from 3 to 30 phr, a filler such as acarbon black from 20 to 100 phr, and an exfoliating clay from 0.5 to 20phr in one embodiment, and from 2 to 15 phr in another embodiment. Thecure agents such as phenolic resins, sulfur, stearic acid, and zincoxide, may be present from 0.1 to 10 phr.

In another embodiment, the composition may be a halogenated butyl rubbercomponent from 75 to 97 phr in one embodiment, and from 80 to 97 phr inanother embodiment, and processing aid present from 3 to 30 phr, afiller such as a carbon black from 20 to 100 phr, and an exfoliatingclay from 0.5 to 20 phr in one embodiment, and from 2 to 15 phr inanother embodiment. The cure agents such as phenolic resins, sulfur,stearic acid, and zinc oxide, may be present from 0.1 to 10 phr.

In yet another embodiment, the composition may be a halogenated butylrubber component from 85 to 97 phr in one embodiment, and from 90 to 97phr in another embodiment, and processing aid present from 3 to 30 phr,a filler such as a carbon black from 20 to 100 phr, and an exfoliatingclay from 0.5 to 20 phr in one embodiment, and from 2 to 15 phr inanother embodiment. The cure agents such as phenolic resins, sulfur,stearic acid, and zinc oxide, may be present from 0.1 to 10 phr.

The isobutylene-based elastomer useful in the invention can be blendedwith various other rubbers or plastics as disclosed herein, inparticular thermoplastic resins such as nylons or polyolefins such aspolypropylene or copolymers of polypropylene. These compositions areuseful in air barriers such as bladders, envelopes, tire innertubes,tire innerliners, air sleeves (such as in air shocks), diaphragms, aswell as other applications where high air or oxygen retention isdesirable. In one embodiment, the cured composition when formed into anarticle has a MOCON oxygen transmission at 60° C. of about 40.0cc-mm/m²-day-mmHg, alternatively, about 45.0 cc-mm/m²-day-mmHg,alternatively, about 50.0 cc-mm/m²-day-mmHg, or alternatively, about75.0 cc-mm/m²-day-mmHg in another embodiment.

In one embodiment, an air barrier can be made by the method of combiningat least one random copolymer comprising a C₄ to C₇ isomonoolefinderived unit, at least one filler, and functionalized polymericprocessing aid having a number average molecular weight greater than400, and at least one cure agent; and curing the combined components asdescribed above.

In certain embodiments, the elastomeric compositions may optionallycomprise:

-   -   a) at least one filler, for example, calcium carbonate, clay,        mica, silica, silicates, talc, titanium dioxide, starch, wood        flower, carbon black, or mixtures thereof;    -   b) at least one clay, for example, montmorillonite, nontronite,        beidellite, volkonskoite, laponite, hectorite, saponite,        sauconite, magadite, kenyaite, stevensite, vermiculite,        halloysite, aluminate oxides, hydrotalcite, or mixtures thereof,        optionally, treated with modifying agents;    -   c) at least one processing oil, for example, aromatic oil,        naphthenic oil, paraffinic oil, or mixtures thereof;    -   d) at least one processing aid, for example, plastomer,        polybutene, polyalphaolefin oils, or mixtures thereof;    -   e) at least one cure package or curative or wherein the        elastomeric composition has undergone at least one process to        produce a cured composition;    -   f) any combination of a-e.

The elastomeric compositions as described above may be used in themanufacture of air membranes such as innerliners and innertubes used inthe production of tires. Methods and equipment used to manufacture theinnerliners and tires are well known in the art. (See, e.g., U.S. Pat.No. 6,834,695, U.S. Pat. No. 6,832,637, U.S. Pat. No. 6,830,722, U.S.Pat. No. 6,822,027, U.S. Pat. No. 6,814,116, U.S. Pat. No. 6,805,176,U.S. Pat. No. 6,802,922, U.S. Pat. No. 6,802,351, U.S. Pat. No.6,799,618, U.S. Pat. No. 6,796,348, U.S. Pat. No. 6,796,347, U.S. Pat.No. 6,617,383, U.S. Pat. No. 6,564,625, and U.S. Pat. No. 6,538,066).The invention is not limited to any particular method of manufacture forarticles such as innerliners or tires.

Industrial Applicability

The elastomeric compositions of the invention may be extruded,compression molded, blow molded, injection molded, and laminated intovarious shaped articles including fibers, films, laminates, layers,industrial parts such as automotive parts, appliance housings, consumerproducts, packaging, and the like.

In particular, the elastomeric compositions are useful in articles for avariety of tire applications such as truck tires, bus tires, automobiletires, motorcycle tires, off-road tires, aircraft tires, and the like.The elastomeric compositions may either be fabricated into a finishedarticle or a component of a finished article such as an innerliner for atire. The article may be selected from air barriers, air membranes,films, layers (microlayers and/or multilayers), innerliners, innertubes,sidewalls, treads, bladders, envelopes, and the like.

In another application, the elastomeric compositions may be employed inair cushions, pneumatic springs, air bellows, hoses, accumulator bags,and belts such as conveyor belts or automotive belts.

They are useful in molded rubber parts and find wide applications inautomobile suspension bumpers, auto exhaust hangers, and body mounts.

Additionally, the elastomeric compositions may also be used asadhesives, caulks, sealants, and glazing compounds. They are also usefulas plasticizers in rubber formulations; as components to compositionsthat are manufactured into stretch-wrap films; as dispersants forlubricants; and in potting and electrical cable filling materials.

In yet other applications, the elastomer(s) or elastomeric compositionsof the invention are also useful in chewing-gum, as well as in medicalapplications such as pharmaceutical stoppers and closures, coatings formedical devices, and the arts for paint rollers.

All priority documents, patents, publications, and patent applications,test procedures (such as ASTM methods), and other documents cited hereinare fully incorporated by reference to the extent such disclosure is notinconsistent with this invention and for all jurisdictions in which suchincorporation is permitted.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present invention,including all features which would be treated as equivalents thereof bythose skilled in the art to which the invention pertains.

EXAMPLES Physical Test Methods

Test methods are summarized in Table 1.

Cure properties were measured using a MDR 2000 and 0.5 degree arc or ODR2000 and 3 degree arc at the indicated temperature. Test specimens werecured at the indicated temperature, typically from 150° C. to 160° C.,for a time corresponding to t90+ appropriate mold lag. The values “MH”and “ML” used here and throughout the description refer to “maximumtorque” and “minimum torque”, respectively. The “MS” value is the Mooneyscorch value, the “ML(1+4)” value is the Mooney viscosity value. Theerror (2π) in the later measurement is ±0.65 Mooney viscosity units. Thevalues of “t” are cure times in minutes, and “ts” is scorch time” inminutes.

When possible, standard ASTM tests were used to determine the curedcompound physical properties (see Table 1). Stress/strain properties(tensile strength, elongation at break, modulus values, energy to break)were measured at room temperature using an Instron 4202 or an InstronSeries IX Automated Materials Testing System 6.03.08. Tensilemeasurements were done at ambient temperature on specimens (dog-boneshaped) width of 0.25 inches (0.62 cm) and a length of 1.0 inches (2.5cm) length (between two tabs) were used. The thickness of the specimensvaried and was measured manually by Mitutoyo Digimatic Indicatorconnected to the system computer. The specimens were pulled at acrosshead speed of 20 inches/min. (51 cm/min.) and the stress/straindata was recorded. The average stress/strain value of at least threespecimens is reported. The error (2π) in Tensile strength measurementsis ±0.47 MPa units. The error (2π) in measuring 100% Modulus is ±0.11MPa units; the error (2π) in measuring Elongation at break is ±13%units. Shore A hardness was measured at room temperature by using aZwick Duromatic.

Oxygen permeability was measured using a MOCON OxTran Model 2/61operating under the principle of dynamic measurement of oxygen transportthrough a thin film as published by Pasternak et al. in 8 JOURNAL OFPOLYMER SCIENCE: PART A-2, P 467 (1970). The units of measure arecc-mm/m²-day-mmHg. Generally, the method is as follows: flat film orrubber samples are clamped into diffusion cells which are purged ofresidual oxygen using an oxygen free carrier gas. The carrier gas isrouted to a sensor until a stable zero value is established. Pure oxygenor air is then introduced into the outside of the chamber of thediffusion cells. The oxygen diffusing through the film to the insidechamber is conveyed to a sensor which measures the oxygen diffusionrate.

Permeability was tested by the following method. Thin, vulcanized testspecimens from the sample compositions were mounted in diffusion cellsand conditioned in an oil bath at 65° C. The time required for air topermeate through a given specimen is recorded to determine its airpermeability. Test specimens were circular plates with 12.7-cm diameterand 0.38-mm thickness. The error (2π) in measuring air permeability is±0.245 (×10⁸) units.

In one embodiment, the composition has a MOCON at 60° C. of less than56.0×10⁻⁸ cc-mm/m²-day-mmHg.

In another embodiment, the composition has a MOCON at 60° C. of lessthan 50.0×10⁻⁸ cc-mm/m²-day-mmHg.

In yet another embodiment, the composition has a MOCON at 60° C. of lessthan 45.0×10⁻⁸ cc-mm/m²-day-mmHg.

The composition can be used to make any number of articles. In oneembodiment, the article is selected from tire curing bladders, tirecuring envelopes, tire innerliners, tire innertubes, and air sleeves.Other useful goods that can be made using compositions of the inventioninclude hoses, seals, molded goods, cable housing, and other articlesdisclosed in THE VANDERBILT RUBBER HANDBOOK, P 637-772 (Ohm, ed., R.T.Vanderbilt Company, Inc. 1990).

TABLE 1 Test Methods Parameter Units Test Mooney Viscosity (polymer) ML1 + 8, 125° C., MU ASTM D1646 Mooney Viscosity (composition) ML 1 + 4,100° C., MU ASTM D1646 Green Strength (100% Modulus) PSI ASTM D412 MOCON(@ 60° C.) cc-mm/m²-day-mmHg See text Air Permeability (@ 65° C.)(cm³-cm/cm²-sec-atm) ×10⁸ See text Brittleness ° C. ASTM D746 MooneyScorch Time T5, 125° C., minutes ASTM D1646 Oscillating Disk Rheometer(ODR) @ 160° C., ±3°arc Moving Die Rheometer (MDR) @ ASTM D2084 160° C.,± 0.5°arc ML deciNewton.meter MH dNewton.m ts2 minutes t50 minutes t90minutes Physical Properties, press cured Tc 90 + 2 min @ 160° C.Hardness Shore A ASTM D2240 Modulus 20%, 100%, 300% MPa ASTM D412 die CTensile Strength MPa Elongation at Break % Energy to Break N/mm (J) HotAir Aging, 72 hrs. @ 125° C. ASTM D573 Hardness Shore A Modulus 20%,100%, 300% MPa Tensile Strength MPa Elongation at Break % Energy toBreak N/mm (J) DeMattia Flex mm @ kilocycles ASTM D813 modified

TABLE 2 Various Components in the Compositions Component BriefDescription Commercial Source Bromobutyl 2222 Brominated ExxonMobilChemical Poly(isobutylene-co- Company (Houston, TX) isoprene), MooneyViscosity (1 + 8, 125° C.) of from 27-37 MU Bromobutyl-6222 Brominatedbutyl rubber ExxonMobil Chemical with styrene block Company (Houston,TX) copolymer EXXPRO ™ 01-5 10 wt % PMS, 0.85 mol % ExxonMobil ChemicalBrPMS, Mooney viscosity Company (Houston, TX) of 45 ± 5 MU (1 + 8, 125°C.) N660 Carbon black Sid Richardson Carbon Company (Fort Worth, TX)CLOISITE ™ 20A Dimethylditallowammonium Southern Clay Products chloridemodified (Gonzalez, TX) montmorillonite clay CALSOL ™ 810 Naphthenic OilR. E. Carroll, Inc ASTM Type 103 (Trenton, NJ) VIVATEC 500 TDAE (TreatedDistillated Hansen & Rosenthal Group Aromatic Extract) oil (Hamburg,Germany) PARAPOL ™ C₄ raffinate ExxonMobil Chemical Company (Houston,TX) TPC 5130 Polyisobutylene Texas Petrochemicals (Houston, TX) PIBSAPolyisobutylene succinic Infineum International anhydride Ltd. (Linden,NJ) Rosin Oil MR-1085 A Tackifier, including Sovereign Chemicalunsaturated cyclic (Akron, OH) carboxylic acids SP-1068 Alkyl phenolSchenectady Int. formaldehyde resin (Schenectady, NY) STRUKTOL ™ 40 MSComposition of aliphatic- Struktol Co. of America aromatic-naphthenic(Stow, OH) resins KADOX ™ 911 High Purity French Zinc Corp. of AmericaProcess Zinc Oxide (Monaca, PA) KADOX ™ 930 High Purity French ZincCorp. of America Process Zinc Oxide (Monaca, PA) MBTS2-Mercaptobenzothiazole R. T. Vanderbilt (Norwalk, disulfide CT) orElastochem (Chardon, OH) MAGLITE-K ™ Magnesium Oxide C. P. Hall Co.(Stow, OH)Testing of Functionalized Polymer

The functionalized polymer polyisobutylene succinic anhydride (PIBSA,Expt 3) was incorporated into a bromobutyl rubber tire innerlinerformulation along with other rubber compounding ingredients (see Table2) by mixing in a two-step process in a Krupp internal mixer equippedwith intermeshing rotors. A 1200-gram batch size was used for eachmixing stage. The first stage was mixed at a continuous rotor speed of60 rpm by adding all of the polymers and mixing for 30 seconds. 75% ofthe carbon black was then added and the mixture was continued to bemixed another 30 seconds. The non-black fillers (clay, etc.) and theprocessing aids (processing oil, NFP, functional polybutene of thepresent invention) were added and the mixture was continued to be mixedfor another 30 seconds. The remaining carbon black and the resins(Struktol 40MS, SP-1068) were added and the mixture continued to bemixed until a total of 240 seconds elapsed or a mixer temperature of300° F. was reached, whichever occurred first. The second stage wasmixed (1200-gram batch) in the Krupp internal mixer equipped withintermeshing rotors at a rotor speed of 45 rpm. Maximum cooling was usedto regulate the temperature of the internal mixer. The step onemasterbatch stock and all cure antidegredants (stearic acid, zinc oxide,sulfur, accelerator) were added and the mixture was continued to bemixed until a total of 150 seconds elapsed or a mixer temperature of220° F. was reached, whichever occurred first. An open two-roll mill wasused to sheet out the stocks after each Krupp mixing step. Compoundswith a naphthenic processing oil, Control 1, and the NFP polyisobutyleneprocessing aid, Control 2, were similarly prepared as comparativeexamples. Formulations are shown in Table 3.

TABLE 3 Bromobutyl Rubber Innerliner Test Formulations. IngredientControl 1 Control 2 Expt 3 BIIR 2222 100 100 100 NR, SMR 20 CarbonBlack, N660 60 60 60 SP-1068 4 4 4 Struktol 40MS 7 7 7 Processing Oil,Calsol 810 8 Polybutene, Parapol 950 8 Functionalized Polybutene, 8PIBSA C-9220 Stearic acid 1 1 1 Zinc Oxide, Kadox 911 1 1 1 Sulfur 0.50.5 0.5 MBTS 1.25 1.25 1.25

Results of cure and cured physical property testing indicate that use ofthe functionalized polymer PIBSA (Expt 3) maintains the reduced MOCONAir Permeability obtained when using a PIB NFP processing aid (Control2) in place of the naphthenic processing oil (Control 1) in the tireinnerliner formulation. Expt 3 has a higher Mooney scorch value comparedto that of the PIB NFP (Control 2) and a higher ts2 cure time valuecompared to that of the naphthenic processing oil (Control 1) and PIBNFP (Control 2), which can allow for easier processing in downstreamtire manufacturing steps. Expt 3 has a lower DeMattia crack growth valuecompared to that of the naphthenic processing oil (Control 1) or the PIBNFP (Control 2), see Table 4. Other cure and cured physical propertiesare maintained.

TABLE 4 Properties of Bromobutyl Rubber Innerliner Test Formulations.Properties Control 1 Control 2 Expt 3 MDR @160 C., 0.5 arc mh-ml 3.613.03 2.97 ts2, minutes 4.97 4.90 5.75 t50, minutes 4.59 3.86 4.34 t90,minutes 10.32 7.97 12.40 Viscosity 1 + 4 (100° C.) 57.6 60.1 57.7 Scorch@ 135 C., 5 PT, minutes 17.43 12.97 17.49 Hardness, Shore A 49.70 49.3052.70 Aged Hardness, Shore A 63.90 59.90 64.30 Stress/Strain 20%Modulus, MPa 0.47 0.48 0.51 100% Modulus, MPa 1.81 1.75 1.48 300%Modulus, MPa 2.93 2.84 2.31 Tensile, MPa 9.57 9.63 8.23 Elongation, %868 876 847 Energy to break, N/mm 12.48 12.33 9.77 Aged Stress/Strain(72 hrs@125 C.) 20% Modulus, MPa 0.80 0.60 0.77 100% Modulus, MPa 1.991.51 1.63 300% Modulus, MPa 5.74 4.64 4.65 Tensile, MPa 8.15 7.58 7.31Elongation, % 570 650 611 Energy to break, N/mm 8.70 9.11 8.07 DeMattiaFlex Crack Growth @1742 kcycles, mm 11.8 5.8 3.1 Aged DeMattia Flex (72hr @125 C.) Crack Growth @1741 kcycles, mm 15.8 9.1 8.8 Adhesion TearResistance, N/mm 13.85 12.24 10.22 MOCON Air Permeability 52.64 45.1346.88 cc · mm/(m2 · day · mmHg)

The functionalized polymer polyisobutylene succinic anhydride (PIBSA,Expt 6) was incorporated into a bromobutyl rubber tire innerlinerformulation along with other rubber compounding ingredients (see Table2) by mixing by mixing in a Krupp internal mixer in a two-step processessentially identical to that of Control Compounds 1 and 2, andExperimental Compound 3. Compounds with a naphthenic processing oil,Control 4, and the NFP polyisobutylene processing aid, Control 5, weresimilarly prepared as comparative examples. Formulations are shown inTable 5.

TABLE 5 Bromobutyl Rubber Innerliner Test Formulations. Compound Control4 Control 5 Expt 6 BIIR 2222 100 100 100 Carbon Black, N660 60 60 60Clay, Cloisite 20A 0 5 5 Processing Oil, Calsol 810 8 PIB, TPC 5230 8PIBSA 55 8 SP-1068 4 4 4 Struktol 40MS 7 7 7 Stearic acid 1 1 1 ZincOxide, Kadox 911 1 1 1 Sulfur 0.5 0.5 0.5 MBTS 1.25 1.25 1.25

Results of cure and cured physical property testing indicate that use ofthe functionalized polymer PIBSA (Expt 6) maintains the reduced MOCONAir Permeability obtained when using a PIB NFP processing aid (Control5) in place of the naphthenic processing oil (Control 4) in the tireinnerliner formulation. Expt 6 has a higher Mooney scorch value comparedto that of the naphthenic processing oil (Control 4) and the PIB NFP(Control 5), and a higher ts2 cure time value compared to that of thenaphthenic processing oil (Control 4), which can allow for easierprocessing in downstream tire manufacturing steps. Other cure and curedphysical properties are maintained, Table 6.

TABLE 6 Properties of Bromobutyl Rubber Innerliner Test Formulations.Property Control 4 Control 5 Expt 6 MDR @160, 0.5 deg arc ml, dN · m 1.31.4 1.3 mh, dN · m 4.7 5.3 4.3 ts2, min. 4.5 6.7 6.9 t50, min. 4.0 6.45.2 t90, min. 10.6 12.3 11.3 Mooney Viscosity, ML (1 + 4)@ 53.1 52.850.1 100° C. Mooney Scorch @135 C., t5 12.7 16.0 18.0 Shore A Hardness43.3 49.1 47.9 Stress/Strain 100% Modulus, MPa 0.90 1.18 1.04 300%Modulus, MPa 2.76 3.59 2.82 Tensile strength, MPa 8.6 9.6 8.9 Elongationat break, % 851 776 822 Energy to break, MPa 11.2 11.0 10.5 MOCON AirPermeability cc · mm/(m2 · day · mmHg) 69.0 53.3 58.5 ARES @60 C., 10Hz, 2% Strain G′, MPa 2.80 3.01 2.81 G″, MPa 0.48 0.63 0.60 G*, MPa 2.843.07 2.87 Tangent delta 0.173 0.210 0.212

The functionalized polymer polyisobutylene succinic anhydride (PIBSA,Expt 9) was incorporated into a star-branched bromobutyl rubber tireinnerliner formulation along with other rubber compounding ingredients(see Table 2) by mixing in a Krupp internal mixer in a two-step processessentially identical to that of Control Compounds 1 and 2, andExperimental Compound 3. Compounds with a naphthenic processing oil,Control 7, and the NFP polyisobutylene processing aid, Control 8, weresimilarly prepared as comparative examples. Formulations are shown inTable 7.

TABLE 7 Star-Branched Bromobutyl Rubber Innerliner Test Formulations.Compound Control 7 Control 8 Expt 9 SBB 6222 100 100 100 Carbon Black,N660 60 60 60 Clay, Cloisite 20A 0 5 5 Processing Oil, Calsol 810 8 PIB,TPC 5230 8 PIBSA 55 8 SP-1068 4 4 4 Struktol 40MS 7 7 7 Stearic acid 1 11 Zinc Oxide, Kadox 911 1 1 1 Sulfur 0.5 0.5 0.5 MBTS 1.25 1.25 1.25

Results of cure and cured physical property testing indicate that use ofPIBSA (Expt 9) maintains the reduced MOCON Air Permeability obtainedwhen using a PIB NFP processing aid (Control 8) in the tire innerlinerformulation compared to the naphthenic processing oil (Control 7). Expt9 has a higher Mooney scorch value compared to that of the naphthenicprocessing oil (Control 7) and the PIB NFP (Control 8), and a higher ts2cure time value compared to that of the naphthenic processing oil(Control 7), which can allow for easier processing in downstream tiremanufacturing steps. Other cure and cured physical properties aremaintained, Table 8.

TABLE 8 Properties of Star-Branched Bromobutyl Rubber Innerliner TestFormulations. Property Control 7 Control 8 Expt 9 MDR @160, 0.5 deg arcml, dN · m 1.2 1.3 1.2 mh, dN · m 4.2 5.2 3.8 ts2, min. 6.2 8.1 8.9 t50,min. 4.9 7.8 6.3 t90, min. 11.0 13.8 11.7 Mooney Viscosity, ML (1 + 4)@50.6 49.9 46.9 100° C. Mooney Scorch @135 C., t5 14.8 18.2 21.5 Shore AHardness 44.5 50.7 45.5 Stress/Strain 100% Modulus, MPa 0.93 1.33 1.04300% Modulus, MPa 2.81 4.05 2.91 Tensile strength, MPa 8.2 9.4 8.2Elongation at break, % 824 759 852 Energy to break, MPa 10.2 11.5 10.8MOCON Air Permeability cc · mm/(m2 · day · mmHg) 70.0 53.5 55.5 ARES @60C., 10 Hz, 2% Strain G′, MPa 2.88 3.03 2.86 G″, MPa 0.46 0.57 0.60 G*,MPa 2.91 3.09 2.92 Tangent delta 0.158 0.188 0.211

The functionalized polymer polyisobutylene succinic anhydride (PIBSA,Expt 13) was incorporated into a brominatedisobutylene-co-para-methylstyrene rubber tire innerliner formulationalong with other rubber compounding ingredients (see Table 2) by mixingin a Krupp internal mixer in a two-step process essentially identical tothat of Control Compounds 1 and 2, and Experimental Compound 3.Compounds with a naphthenic processing oil, Controls 10 and 11, and theNFP polyisobutylene processing aid, Control 12, were similarly preparedas comparative examples. Formulations are shown in Table 9.

TABLE 9 Brominated-isobutylene-co-para-methylstyrene Rubber InnerlinerTest Formulations. Ingredient Control 10 Control 11 Control 12 Expt 13Exxpro MDX 89-1 100 100 100 100 Carbon Black, N660 60 55 55 55 Closite25A 4 4 4 Carbon Black, N660 15 15 15 15 SP-1068 4 4 4 4 Struktol 40MS 77 7 7 Stearic acid 1 1 1 1 Processing Oil, Calsol 810 8 8 PIB, Parapol1300 8 Functionalized PIB, 8 PIBSA C9220 Zinc Oxide, Kadox 911 1 1 1 1Sulfur 0.5 0.5 0.5 0.5 MBTS 1.25 1.25 1.25 1.25

Results of cure and cured physical property testing indicate that use ofPIBSA (Expt 13) maintains the reduced MOCON Air Permeability obtainedwhen using a PIB NFP processing aid (Control 12) in the tire innerlinerformulation compared to the naphthenic processing oil (Controls 10 and11). Expt 13 higher ts2 cure time value compared to that of thenaphthenic processing oil (Controls 10 and 11) and the PIB NFP (Control12). Expt has a lower Mooney viscosity value compared to the PIB NFP(Control 12), which can allow for easier processing in downstream tiremanufacturing steps. Other cure and cured physical properties aremaintained, Table 10.

TABLE 10 Properties of Brominated-isobutylene-co-para-methylstyreneRubber Innerliner Test Formulations. Property Control 10 Control 11Control 12 Expt 13 Cure, ODR ml, dN · m 8.3 9.8 11.3 8.7 mh, dN · m 32.341.7 35.7 33.5 ts2, min. 4.9 4.7 5.1 11.8 t50, min. 8.5 9.8 10.0 16.0t90, min. 12.9 18.1 17.8 20.6 Mooney Viscosity, ML (1 + 4)@100° C. 56.054.9 59.3 55.6 Mooney Scorch @135 C., T5 20.9 6.3 6.8 — Hardness, ShoreA 54.7 55.3 55.3 58.3 Hardness, Shore A aged 72 hr@125 C. 61.7 58.5 53.958.7 Stress/Strain 100% Modulus, MPa 1.22 1.34 1.48 1.32 300% Modulus,MPa 3.52 3.96 4.20 3.18 Tensile strength, MPa 9.02 10.29 10.73 9.51Elongation at break, % 928 925 902 1006 Energy to break, MPa 13.92 15.6315.64 15.52 Stress/Strain, aged 72 hr@125 C. 100% Modulus, MPa 2.59 2.601.98 2.16 300% Modulus, MPa 6.98 6.89 5.66 5.51 Tensile strength, MPa10.18 10.60 10.84 10.29 Elongation at break, % 627 668 763 773 Energy tobreak, MPa 11.56 13.50 14.16 14.24 MOCON Air Permeability cc · mm/(m2 ·day · mmHg) 47.8 46.3 37.7 35.9 Adhesion to NR Tear Resistance, N/mm1.75 6.45 5.76 7.25 Adhesion to SBR Tear Resistance, N/mm 0.59 1.56 1.520.70

The functionalized polymer polyisobutylene succinic anhydride (PIBSA,Expt 16) was incorporated into a brominatedisobutylene-co-para-methylstyrene rubber tire innerliner formulationalong with other rubber compounding ingredients (see Table 2) by mixingin a Krupp internal mixer in a two-step process essentially identical tothat of Control Compounds 1 and 2, and Experimental Compound 3.Compounds with a naphthenic processing oil, Control 14, and the NFPpolyisobutylene processing aid, Control 15, were similarly prepared ascomparative examples. Formulations are shown in Table 11.

TABLE 11 Brominated-isobutylene-co-para-methylstyrene Rubber InnerlinerTest Formulations. Compound Control 14 Control 15 Expt 16 Exxpro MDX01-5 100 100 100 Carbon Black, N660 60 60 60 Clay, Cloisite 20A 0 5 5Processing Oil, Calsol 810 8 PIB, TPC 5230 8 PIBSA 55 8 SP-1068 4 4 4Struktol 40MS 7 7 7 Stearic acid 1 1 1 Zinc Oxide, Kadox 911 1 1 1Sulfur 0.5 0.5 0.5 MBTS 1.25 1.25 1.25

Results of cure and cured physical property testing indicate that use ofPIBSA (Expt 16) maintains the reduced MOCON Air Permeability obtainedwhen using a PIB NFP processing aid (Control 15) in the tire innerlinerformulation compared to the naphthenic processing oil (Control 14). Expt16 higher ts2 cure time value compared to that of the naphthenicprocessing oil (Control 14) and the PIB NFP (Control 15), which canallow for easier processing in downstream tire manufacturing steps.Other cure and cured physical properties are maintained, Table 12.

TABLE 12 Properties of Brominated-isobutylene-co-para-methylstyreneRubber Innerliner Test Formulations. Property Control 14 Control 15 Expt16 MDR @160, 0.5 deg arc ml, dN · m 1.7 2.1 1.9 mh, dN · m 6.4 6.5 5.9ts2, min. 5.0 8.8 12.7 t50, min. 5.4 9.2 12.7 t90, min. 8.4 16.3 18.0Mooney Viscosity, ML (1 + 4)@ 63.6 69.4 63.0 100° C. Mooney Scorch @135C., t5 13.8 6.1 49.2 Shore A Hardness 49.5 51.5 52.7 Stress/Strain 100%Modulus, MPa 1.51 2.62 1.97 300% Modulus, MPa 4.63 7.62 5.52 Tensilestrength, MPa 9.7 12.0 10.4 Elongation at break, % 817 586 769 Energy tobreak, MPa 13.9 12.8 14.6 MOCON Air Permeability cc · mm/(m2 · day ·mmHg) 56.2 42.0 42.7 ARES @60 C., 10 Hz, 2% Strain G′, MPa 2.77 2.873.33 G″, MPa 0.37 0.38 0.54 G*, MPa 2.79 2.89 3.38 Tangent delta 0.1340.131 0.161

The functionalized polymer polyisobutylene succinic anhydride (PIBSA,Expt 19) was incorporated into a brominatedisobutylene-co-para-methylstyrene rubber tire innerliner formulationalong with other rubber compounding ingredients (see Table 2) by mixingin tangential mixers using a classical 2-stage mixing cycle. The firstmixing step used a GK 400 mixer (about 450 lb batch size) and lasted 4minutes. Carbon black, TDAE oil, SP-1068 tackifier resin and stearicacid were automatically weighed to appropriate batch amounts anddirectly injected into the mixer at the appropriate time and/ortemperature. The second stage was mixed in GK 160 internal mixer (about150 lb batch size). Compounds with a TDAE processing oil (Controls 17and 18) were similarly prepared as comparative examples for Experimental19. Formulations are shown in Table 13.

TABLE 13 Brominated-isobutylene-co-para-methylstyrene Rubber InnerlinerTest Formulations. Compound Control 17 Control 18 Expt 19 Exxpro MDX01-5 100 100 100 Carbon Black, N660 60 60 60 Clay, Cloisite 20A 0 5 5Processing Oil, TDAE 8 8 PIBSA 8 SP-1068 4 4 4 Struktol 40MS 7 7 7Stearic acid 1 1 1 Zinc Oxide, Kadox 911 1 1 1 Sulfur 0.5 0.5 0.5 MBTS1.25 1.25 1.25

Results of cure and cured physical property testing indicate that use ofPIBSA (Expt 19) affords reduced MOCON Air Permeability and Aged MOCONAir Permeability values compared to when using a TDAE processing oil(Controls 17 and 18) in the tire innerliner formulation. Expt 19 has ahigher ts2 cure time value compared to that of the TDAE processing oil(Controls 17 and 18), which can allow for easier processing indownstream tire manufacturing steps. Expt 19 has a higher Fatigue tofailure value compared to that of the TDAE processing oil (Controls 17and 18). Other cure and cured physical properties are maintained, Table14.

TABLE 14 Properties of Brominated-isobutylene-co-para-methylstyreneRubber Innerliner Test Formulations. Property Control 17 Control 18 Expt19 Mooney Viscosity ML (1 + 4)@ 70.1 77.0 68.8 100° C. Green Strength,peak load (N) 15.32 23.31 17.93 Green Strength, Time to T75 (min) 5.399.35 3.26 Cure, MDR @160° C. ml, dN · m 1.57 1.91 1.77 mh, dN · m 6.776.62 6.15 ts2, min. 4.53 7.29 13.28 t50, min. 5.04 8.00 13.67 t90, min.8.39 14.25 21.36 Hardness, Shore A 54 56 58 Aged Hardness, Shore A 58 5861 (72 hr@125° C.) Stress/Strain 100% Modulus, MPa 1.93 2.06 2.30 2300%Modulus, MPa 5.87 6.46 6.39 Tensile strength, MPa 11.21 13.14 11.89Elongation at break, % 780.7 799.0 858.7 Energy to break, MPa 18.2 20.720.4 Aged Stress/Strain (72 hr@125° C.) 100% Modulus, MPa 2.96 3.19 3.54300% Modulus, MPa 8.49 8.91 9.30 Tensile strength, MPa 11.66 13.26 12.51Elongation at break, % 534.2 600.7 573.2 Energy to break, MPa 13.1716.44 15.43 Fatigue to Failure (kc to failure) 357860 293901 733870Adhesion to NR Carcass Tear Resistance @100° C. 4.42 1.44 0.92 Mocon AirPermeability cc · mm/(m2 · day · mmHg) 20.5 19.0 16.9 Aged Mocon AirPermeability cc · mm/(m2 · day · mmHg) 18.0 16.1 14.1

1. A process to produce an elastomeric composition, the processcomprising contacting at least one elastomer derived from a C₄ to C₇isomonoolefin with a processing aid, wherein the processing aidcomprises at least one anhydride functionalized polymer, wherein thefunctionalized polymer has a molecular weight, Mn, of from 800 to 2500,and a viscosity of 35 to about 1000 cSt at 100° C., wherein the at leastone elastomer comprises a halogenated butyl rubber, a star-branchedhalogenated butyl rubber, or a halogenated random copolymer ofisobutylene and methylstyrene.
 2. The process of claim 1, wherein the atleast one anhydride group is derived from the group consisting of maleicanhydride, itaconic anhydride, citraconic anhydride, propenyl succinicanhydride, 2-pentenedioic anhydrides, and mixtures thereof.
 3. Theprocess of claim 1, wherein the at least one anhydride group is derivedfrom maleic anhydride.
 4. The process of claim 1, wherein the anhydridefunctionality of the functionalized polymer is in the range of fromabout 0.5 mol % to about 2.0 mol %.
 5. The process of claim 1, whereinthe functionalized polymer comprises C₂-C₁₂ α-olefin derived units orC₄-C₁₀ isoolefin derived units.
 6. The process of claim 1, wherein theat least one elastomer is halogenated with chlorine or bromine.
 7. Anelastomeric composition produced by the process of claim
 1. 8. Theelastomeric composition of claim 7, wherein the elastomeric compositionis made with 30 phr or less of the processing aid.
 9. The elastomericcomposition of claim 7, wherein the elastomeric composition is made with20 phr or less of the processing aid.
 10. The elastomeric composition ofclaim 7, wherein the elastomeric composition further comprises naturalrubber (NR), isoprene rubber (IR), styrene-co-butadiene rubber (SBR),isoprene-co-butadiene rubber (IBR), styrene-isoprene-butadiene rubber(SIBR), ethylene-propylene rubber (EP), ethylene-propylene-diene rubber(EPDM), or mixtures thereof.
 11. The elastomeric composition of claim 7,the elastomeric composition optionally comprises: a) at least one fillerselected from calcium carbonate, clay, mica, silica, silicates, talc,titanium dioxide, starch, wood flower, carbon black, or mixturesthereof; b) at least one clay selected from montmorillonite, nontronite,beidellite, volkonskoite, laponite, hectorite, saponite, sauconite,magadite, kenyaite, stevensite, vermiculite, halloysite, aluminateoxides, hydrotalcite, or mixtures thereof, optionally, treated withmodifying agents; c) at least one processing oil selected from aromaticoil, naphthenic oil, paraffinic oil, or mixtures thereof; d) at leastone non-functionalized polybutene processing aid; e) at least one curepackage or wherein the elastomeric composition has undergone at leastone process to produce a cured composition; or f) any combination ofa-e.
 12. An article produced from the elastomeric composition of claim7.
 13. The article of claim 12, wherein the article has an oxygenpermeability rate of 56.0 cc-mm/m²-day-mmHg or less.
 14. The article ofclaim 12, wherein the article has an Elongation at break value of 650%or higher.
 15. The article of claim 12, wherein the article has a ShoreA hardness value of 60 or lower.
 16. The article of claim 12, whereinthe article has an Energy to break value of 10.0 MPa or higher.
 17. Thearticle of claim 12, wherein the article has a Mooney scorch t5 value at135° C. of 12.5 minutes or higher.
 18. The article of claim 12, whereinthe article is selected from the group consisting of innerliners,bladders, air membranes, innertubes, air barriers, films, layers(microlayers and/or multilayers), treads, and sidewalls.
 19. The processof claim 1, wherein the functionalized polymer does not contain anyaromatic groups or unsaturation.